Henry, Over the last few years, I have been using math problems on Quora <https://www.quora.com/> to polish my J skills. I have solved probably a couple thousand solutions to math problems on Quora using J. Here is a small sample of some of my most recent Quora problem solutions. Do you think these kinds of problems would be appropriate for helping beginners learn J?:
How many 5-digit numbers are there where each digit is greater or equal than the previous one? <https://www.quora.com/How-many-5-digit-numbers-are-there-where-each-digit-is-greater-or-equal-than-the-previous-one/answer/Ellis-Cave> How do you prove that there is no 2-digit number such that the product of its digits is greater than the number itself? <https://www.quora.com/How-do-you-prove-that-there-is-no-2-digit-number-such-that-the-product-of-its-digits-is-greater-than-the-number-itself/answer/Ellis-Cave> The sum of three numbers is 95. The third number is 4 times the second. The first number is 5 more than the second. What are the numbers? <https://www.quora.com/The-sum-of-three-numbers-is-95-The-third-number-is-4-times-the-second-The-first-number-is-5-more-than-the-second-What-are-the-numbers/answer/Ellis-Cave> How do you find two positive numbers such that the sum of the squares of the two numbers is 169 and the difference between the two numbers is 7? <https://www.quora.com/How-do-you-find-two-positive-numbers-such-that-the-sum-of-the-squares-of-the-two-numbers-is-169-and-the-difference-between-the-two-numbers-is-7/answer/Ellis-Cave> What are the square roots of numbers with two odd digits? <https://www.quora.com/What-are-the-square-roots-of-numbers-with-two-odd-digits/answer/Ellis-Cave> What is the smallest natural number that can be written as the sum of two positive primes in more than one way? <https://www.quora.com/What-is-the-smallest-natural-number-that-can-be-written-as-the-sum-of-two-positive-primes-in-more-than-one-way/answer/Ellis-Cave> The 1st, 2nd and 3rd perfect squares are 1, 36 and 64 in the following arithmetic sequence: 1,8,15,22,29,36,43,50,57,64,71,…What is the 100th perfect square of the sequence? <https://www.quora.com/The-1st-2nd-and-3rd-perfect-squares-are-1-36-and-64-in-the-following-arithmetic-sequence-1-8-15-22-29-36-43-50-57-64-71-What-is-the-100th-perfect-square-of-the-sequence/answer/Ellis-Cave> What number is it whose thousands digit is three times as large as the hundreds digits, but two less than the tens digit, if the unit digit is 6, no repetition of digits? <https://www.quora.com/What-number-is-it-whose-thousands-digit-is-three-times-as-large-as-the-hundreds-digits-but-two-less-than-the-tens-digit-if-the-unit-digit-is-6-no-repetition-of-digits/answer/Ellis-Cave> What is the solution of (2+√3) (2-√3)? <https://www.quora.com/What-is-the-solution-of-2+%E2%88%9A3-2-%E2%88%9A3/answer/Ellis-Cave> How do you find the sum of the digits of 2^1000? <https://www.quora.com/How-do-you-find-the-sum-of-the-digits-of-2-1000/answer/Ellis-Cave> If 10^5< K < 10^6, then what is the number of different values of K such that the sum of digits of K is 2? <https://www.quora.com/If-10-5-K-10-6-then-what-is-the-number-of-different-values-of-K-such-that-the-sum-of-digits-of-K-is-2/answer/Ellis-Cave> Let a be the sum of digits of 5555^5555. Let b be the sum of digits of a. Let c be the sum of digits of b. What is the value of c? <https://www.quora.com/Let-a-be-the-sum-of-digits-of-5555-5555-Let-b-be-the-sum-of-digits-of-a-Let-c-be-the-sum-of-digits-of-b-What-is-the-value-of-c/answer/Ellis-Cave> A 5-digit number (in base 10) has digits k, k + 1, k + 2, 3k, k + 3 in that order, fromleft to right. If this number is m2 for some natural number m, what is the sum of the digits of m? <https://www.quora.com/A-5-digit-number-in-base-10-has-digits-k-k-1-k-2-3k-k-3-in-that-order-from-left-to-right-If-this-number-is-m-2-for-some-natural-number-m-what-is-the-sum-of-the-digits-of-m/answer/Ellis-Cave> How many positive integers less than 1,000 can be formed using the digits 1,2,3,4,5 and 6 if no digit may be repeated? <https://www.quora.com/How-many-positive-integers-less-than-1-000-can-be-formed-using-the-digits-1-2-3-4-5-and-6-if-no-digit-may-be-repeated/answer/Ellis-Cave> If a 3-digit number is k times larger than its digits' sum, what is the minimum value for k? <https://www.quora.com/If-a-3-digit-number-is-k-times-larger-than-its-digits-sum-what-is-the-minimum-value-for-k/answer/Ellis-Cave> How many numbers between 1000 and 3000 can be formed from the digits 1, 2, 3,4,5? <https://www.quora.com/How-many-numbers-between-1000-and-3000-can-be-formed-from-the-digits-1-2-3-4-5/answer/Ellis-Cave> How many numbers between 1000-9999 are neither divisible by 3 or have a 3, 6 or 9 in them? <https://www.quora.com/How-many-numbers-between-1000-9999-are-neither-divisible-by-3-or-have-a-3-6-or-9-in-them/answer/Ellis-Cave> How many different ways are there to select 4 numbers out of 1, 2, and 20 given that the sum of those four numbers is divisible by 4? <https://www.quora.com/How-many-different-ways-are-there-to-select-4-numbers-out-of-1-2-and-20-given-that-the-sum-of-those-four-numbers-is-divisible-by-4/answer/Ellis-Cave> How many 5-digit numbers with all digits nonzero and no digit repeated are divisible by 25? <https://www.quora.com/How-many-5-digit-numbers-with-all-digits-nonzero-and-no-digit-repeated-are-divisible-by-25/answer/Ellis-Cave> What is the last digit of a cube? <https://www.quora.com/What-is-the-last-digit-of-a-cube/answer/Ellis-Cave> How many 4 digit numbers are divisible by 36, and those numbers are in the format of 6_4_ with 6 and 4 needing to be in the places they are shown in for all the multiples and the blank spaces can have any single digit number? <https://www.quora.com/How-many-4-digit-numbers-are-divisible-by-36-and-those-numbers-are-in-the-format-of-6_4_-with-6-and-4-needing-to-be-in-the-places-they-are-shown-in-for-all-the-multiples-and-the-blank-spaces-can-have-any-single/answer/Ellis-Cave> The average of 5 consecutive odd numbers is 25. What is the smallest of these numbers? <https://www.quora.com/The-average-of-5-consecutive-odd-numbers-is-25-What-is-the-smallest-of-these-numbers/answer/Ellis-Cave> What is the sum of every odd number from one to twenty thousand? <https://www.quora.com/What-is-the-sum-of-every-odd-number-from-one-to-twenty-thousand/answer/Ellis-Cave> A vendor bought 144 fruits and packed them in boxes. Some boxes contained 12 fruits others contained 15 fruits. If there were more boxes containing 12 fruits each than 15 fruits each, calculate the number of boxes each containing 15 fruits? <https://www.quora.com/A-vendor-bought-144-fruits-and-packed-them-in-boxes-Some-boxes-contained-12-fruits-others-contained-15-fruits-If-there-were-more-boxes-containing-12-fruits-each-than-15-fruits-each-calculate-the-number-of-boxes-each/answer/Ellis-Cave> How many ten-digit numbers satisfy both conditions: I (Each of the numbers 0 9, 8, 7, 6, 5, 4, 3, 2, 1, appears exactly once. ii) All numbers except 9 are adjacent to a number greater than it.? <https://www.quora.com/How-many-ten-digit-numbers-satisfy-both-conditions-I-Each-of-the-numbers-0-9-8-7-6-5-4-3-2-1-appears-exactly-once-ii-All-numbers-except-9-are-adjacent-to-a-number-greater-than-it/answer/Ellis-Cave> How many prime factors does each number from 1 to 10 have? <https://www.quora.com/How-many-prime-factors-does-each-number-from-1-to-10-have/answer/Ellis-Cave> In how many ways can 3-digit odd numbers be formed from 5, 7, 3, 2, and 9? <https://www.quora.com/In-how-many-ways-can-3-digit-odd-numbers-be-formed-from-5-7-3-2-and-9/answer/Ellis-Cave> How many prime numbers up to a million end in a 7 in both base 10 and base 12? <https://www.quora.com/How-many-prime-numbers-up-to-a-million-end-in-a-7-in-both-base-10-and-base-12/answer/Ellis-Cave> The average of 16 consecutive positive integers is 30.5. What is the average of the first 8 integers of this set? <https://www.quora.com/The-average-of-16-consecutive-positive-integers-is-30-5-What-is-the-average-of-the-first-8-integers-of-this-set/answer/Ellis-Cave> What are all possible pairs of integers with a sum greater than or equal to five but less than or equal to twenty-two? <https://www.quora.com/What-are-all-possible-pairs-of-integers-with-a-sum-greater-than-or-equal-to-five-but-less-than-or-equal-to-twenty-two/answer/Ellis-Cave> Find the smallest positive integer whose digits are all ones which is divisible by 3333333? <https://www.quora.com/Find-the-smallest-positive-integer-whose-digits-are-all-ones-which-is-divisible-by-3333333/answer/Ellis-Cave> The sum of the digits in the number 67 is 13. (1) How can we show that the sum of the digits of the integers from 19 to 21 is 15 (2) how can we find the sum of the digits of the integers from 1 to 99? <https://www.quora.com/The-sum-of-the-digits-in-the-number-67-is-13-1-How-can-we-show-that-the-sum-of-the-digits-of-the-integers-from-19-to-21-is-15-2-how-can-we-find-the-sum-of-the-digits-of-the-integers-from-1-to-99/answer/Ellis-Cave> What is the sum of all the even numbers between 75 and 85? <https://www.quora.com/What-is-the-sum-of-all-the-even-numbers-between-75-and-85/answer/Ellis-Cave> How many numbers from 1 to 1,000 are not divisible by 2, 3, 5 and 7? <https://www.quora.com/How-many-numbers-from-1-to-1-000-are-not-divisible-by-2-3-5-and-7/answer/Ellis-Cave> The digits 1 to 9 are used exactly once each to make three 3-digit numbers. The second number is three times the first number. The third number is five times the first number. What is the second number? <https://www.quora.com/The-digits-1-to-9-are-used-exactly-once-each-to-make-three-3-digit-numbers-The-second-number-is-three-times-the-first-number-The-third-number-is-five-times-the-first-number-What-is-the-second-number/answer/Ellis-Cave> The unit of a two-digit number is 2 less than the tens digits. If the number is decreased by 13 and then divided by the sum of the digits, the result is 5. What is the number? <https://www.quora.com/The-unit-of-a-two-digit-number-is-2-less-than-the-tens-digits-If-the-number-is-decreased-by-13-and-then-divided-by-the-sum-of-the-digits-the-result-is-5-What-is-the-number/answer/Ellis-Cave> What is the number of integers between 101 and 199 which are exactly divisible by 5 or 7? <https://www.quora.com/What-is-the-number-of-integers-between-101-and-199-which-are-exactly-divisible-by-5-or-7/answer/Ellis-Cave> How many integers (positive and negative) are divisors of 20? <https://www.quora.com/How-many-integers-positive-and-negative-are-divisors-of-20/answer/Ellis-Cave> What is a number which is of 4 digits and divisible by 3 but not by 9? <https://www.quora.com/What-is-a-number-which-is-of-4-digits-and-divisible-by-3-but-not-by-9/answer/Ellis-Cave> What is a five-digit number divisible by 2, 3, 4, and 9? <https://www.quora.com/What-is-a-five-digit-number-divisible-by-2-3-4-and-9/answer/Ellis-Cave> How many numbers between 1 and 1000 are divisible by 3 and 7 but not 2, 5 or 11? <https://www.quora.com/How-many-numbers-between-1-and-1000-are-divisible-by-3-and-7-but-not-2-5-or-11/answer/Ellis-Cave> How many numbers from 100 to 10000 have EXACTLY 3 of the same digit? <https://www.quora.com/How-many-numbers-from-100-to-10000-have-EXACTLY-3-of-the-same-digit/answer/Ellis-Cave> Assume you have a 3 digit number, the last digit is twice as big as the first digit.The product of all the digits is 14.what is the number? <https://www.quora.com/Assume-you-have-a-3-digit-number-the-last-digit-is-twice-as-big-as-the-first-digit-The-product-of-all-the-digits-is-14-what-is-the-number/answer/Ellis-Cave> How do I prove that 1+2–√+3–√+4–√+…100−−−√<676? <https://www.quora.com/How-do-I-prove-that-1-sqrt-2-sqrt-3-sqrt-4-sqrt-100-676/answer/Ellis-Cave> What are four irrational numbers between 3/4 and 4/5? <https://www.quora.com/What-are-four-irrational-numbers-between-3-4-and-4-5/answer/Ellis-Cave> For positive integer a, b, are there any satisfy 3 (a^2-ab+b^2) = 71(a+b)? <https://www.quora.com/For-positive-integer-a-b-are-there-any-satisfy-3-a-2-ab-b-2-71-a-b/answer/Ellis-Cave> How many numbers from 2000 to 2101 are divisible by 2 or by 3? <https://www.quora.com/How-many-numbers-from-2000-to-2101-are-divisible-by-2-or-by-3/answer/Ellis-Cave> There are many hundreds more like these. Skip Skip Cave Cave Consulting LLC On Wed, May 31, 2023 at 10:01 AM Henry Rich <henryhr...@gmail.com> wrote: > How do you convince someone that J is really different? Examples seem > contrived. > > I am trying something new. I have used J to solve a suite of > programming problems posed by an impartial source, to wit Advent of Code > 2022. Tire-kickers can compare the J solutions against those in other > languages. > > The pages are at https://code.jsoftware.com/wiki/ShareMyScreen . > > IF YOU ARE NEW TO J, you are the person I need to hear from. Where do I > need to add explanatory material, or rewrite a section? > > IF YOU ARE AN OLD J HAND, consider adding your own programs. They can > be from any source as long as you make the solution comprehensible to a > novice. > > I know several users on this list solved the AoC2022 problems; > alternative solution pages would be welcome. > > Henry Rich > > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
