Amicable numbers are a pair of distinct natural numbers (a, b) such that the sum of the proper divisors of a equals b and the sum of the proper divisors of b equals a. Given that (220, y) is a pair…
Question and options
Amicable numbers are a pair of distinct natural numbers (a, b) such that the sum of the proper divisors of a equals b and the sum of the proper divisors of b equals a. Given that (220, y) is a pair of amicable numbers, y equals:
- 225
- 284
- 404
- None of the given options is correct
Answer and explanation
Correct answer: B - 284
Proper divisors of 220 sum to 284, and those of 284 (1+2+4+71+142) sum to 220. So y = 284 (the classic amicable pair).
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