Question

Question 40

$8.4÷$ ___ $=2.1$

Answer 1

Let x be the missing number then
$8.4÷x=2.1\Rightarrow 8.4\times \frac{1}{x}=2.1[\because \text{reciprocal of x}=\frac{1}{x}]\Rightarrow 8.4=2.1x\Rightarrow x=\frac{8.4}{2.1}\Rightarrow x=\frac{84}{21}\times \frac{10}{10}=4\Rightarrow x=4$
Hence, $8.4÷4=2.1$