Question

Aman thinks of a number and subtracts $\frac{5}{2}$ from it. He multiplies the result by 18. The result now obtained is 9 times the same number he thought of. What is the number he thought of?
(3 marks)

Answer 1

Let, the number which Aman initially thought of be$x$.
(0.5 marks)

He subtracts $\frac{5}{2}$ from $x$ and then multiplies it by 18.
$\Rightarrow (x–\frac{5}{2})\times 18$
(0.5 marks)

According to the question,
$(x–\frac{5}{2})\times 18=9\times x\Rightarrow 18x–45=9x\Rightarrow 18x–9x=45\Rightarrow 9x=45\Rightarrow x=\frac{45}{9}\Rightarrow x=5$

Thus, the number that Aman initially thought of is 5.
(2 marks)