Which one of the following numbers is divisible by both 13 and 17?
Show answer & explanation
Correct answer: A
Explanation
Both 13 and 17 are prime.
LCM = 13 × 17 = 221
663 ÷ 221 = 3
425 ÷ 221 ≠ whole number
455 ÷ 221 ≠ whole number
729 ÷ 221 ≠ whole number
Correct answer: 663