What is the number.....................?

Question

One-fifth of a number plus one-seventh of the same number is 108
What is the number?

Answer 1

Let required number = x

One-fifth of the number = x/5

One-seventh of the number = x/7

According to the given problem   x/5+x/7 = 108

7x+5x/35 = 108                                (LCM of 5,7 = 35)

12x/35 = 108

Apply multiplication property, multiply by 35/12 to each side.

x = 108*35/12

x = 9*35

x = 315

check: one-fifth of 315 is 63

one seventh of 315 is 45

63+45 = 108

108=108

So required number is 315