Solution :
Suppose that number is AB
=10A+B
its reverse to be 10B+A
its sum = A+B
(10A+B)/(A+B)=7
10A+B=7(A+B)
10A+B=7A+7B
10A-7A=7B-B
3A=6B
A=2B
if B=1 then A=2
if B=2 then A=4
if B=3 then A=6
if B=4 then A=8
the answer should be
21, 42, 63, or 84
since the smallest number is 21 then the final answer should be 21.
