# Let * be a binary operation on the set of all nonzero real numbers, defined

Question:

Let * be a binary operation on the set of all nonzero real numbers, defined by $a * b=\frac{a b}{5}$ Find the value of x given that2 * (x * 5) = 10.

Solution:

To find: value of $x$

Given: $a^{*} b=\frac{a b}{5}$

$\Rightarrow x^{* 5}=\frac{5 x}{5}=x$

Now $(2 * x)=\frac{2 x}{5}$

$\Rightarrow \frac{2 x}{5}=10 \Rightarrow x=25$