Question

Solve picture question. Mathematics.

Answer 1

Cross multiplication!
$\frac{7}{8}$ = $\frac{x}{24}$
7 × 24 = 8x
168 = 8x

Divide both sides by 8 to isolate x

$\frac{168}{8}$ = $\frac{8x}{8}$
8 and 8 cancels out

21 = x

Answer 2

8*?=24? 8*3=24. So multiply 7 also by 3, and the answer is 21 :)