Multiple choice general knowledge math & puzzles

Paul designs food displays for the local Supermarket. For one of his displays, he wants to set up soup cans in the form of a square pyramid. He's decided to use 10 cans for each side of the square base of the pyramid. If each carton holds 25 soup cans, how many cartons will Paul need to open to build the pyramid?

  1. 15

  2. 20

  3. 16

  4. 10
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The total number of cans in a square pyramid with a base of 10 is the sum of squares from 1 to 10: 1^2 + 2^2 + ... + 10^2 = 385. Dividing 385 by 25 cans per carton equals 15.4. Paul must open 16 cartons to have enough cans. 15 is insufficient, and 10 or 20 are mathematically incorrect.

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