What number should be multiplied by  $9\frac{4}{5}$to get 42?

We have to find the number which should be multiplied by $9\frac{4}{5}$to get 42.

Calculating the number:

$= 42 ÷ 9\frac{4}{5}$

$= 42 ÷ \frac{49}{5}$

$= 42 \times \frac{5}{49}$

$= \frac{6 \times 5}{7}$

$= \frac{30}{7}$
$= 4\frac{2}{7}$

Therefore, The number will be $\mathbf{4}\frac{\mathbf{2}}{\mathbf{7}}$.