Question

Find the number which when multiplied by 7 is increased by 78.

Answer 1

Let the required number be 'x'. Thus, when multiplied by 7, it gives 7x, and x increases by 78.
⇒ 7x = x + 78
Transposing x to LHS, we get
⇒ 7x $-$ x = 78
⇒ 6x = 78
Dividing both sides by 6, we get
⇒ $\frac{6x}{6}=\frac{78}{6}$
⇒ x =13
Thus, the required number is 13.