Question

The sum of proper divisors of 72 (1 and 72 are excluded) is equal to

• A. 195
• B. 122
• C. 194
• D. none of these

Answer 1

Answer: (B)

Proper divisors of $72$ are $2,3,4,8,9,12,18,24,36$
Their sum
$=2+3+4+6+8+9+12+18+24+26$
$=122$