Question

10. Check if the following numbers are perfect numbers. Show working for all. (i) 10 (ii) 25 (iii) 28 (iv) 50

Answer 1

Only iii] is a perfect number

i] Factors of 10 are 1,2,5.

2+5+1 is not equal to ten.

so it is not a perfect number

ii] Factors of 25 are 1,5

1+5 is not equal to 25

so it is not a perfect number

iii] Factors of 28 are 1,2,4,7,14

1+2+4+7+14= 28

so it is a perfect number

iv]Factors of 50 are 1,2,5,10,25

1+2+5+10+25 is not 50

so it is not a perfect number