Question

A number is multiplied and divided by the number 719 The difference between the two results is 312. The given number is:
(a) 133

(b) 49

(c ) 19

(d) 7

Explain with explanation ...

Answer 1

(a) 133

Step-by-step explanation:

Let the number = x

$( x \div \frac{7}{19} )- \frac{7}{19} x = 312 \\ (x \times \frac{19}{7} ) - \frac{7}{19}x = 312 \\ \frac{19}{7}x- \frac{7}{19}x = 312 \\ \frac{(19 \times 19)x - (7 \times 7)x}{7 \times 19} = 312 \\ \frac{361x - 49x}{133} = 312 \\ 312x = 312 \times 133 \\ x = 133$