Question

the sum of two no. a and b is 15. and the sum of their reciprocal 1/a and 1/b is 3/10. find numbers a and b

Answer 1

Let the two numbers be A and B
=>A+B=15                      .............(1)
and
1/A +1/B=3/10
⇒(A+B)/AB = 3/10
from (1)
(A+B)/AB = 15/AB
⇒15/AB = 3/10
⇒AB = 50        ............(2)
solving (1) and (2)
A = 10 and B = 5
or
A = 5 and B = 10

Answer 2

Hope it will be helpful....:-)