Question

If 18 dolls cost ₹630, how many dolls can be bought for ₹455?

• A. 9
• B. 11
• C. 13
• D. 15

Answer 1

The correct option is C

13

Number of dolls $\propto$ Cost of dolls

$\Rightarrow \text{Number of dolls = k}\times \text{Cost of dolls where k is a constant.}$

That is, $\frac{\text{Number of dolls}}{\text{Cost of dolls}}=k$

Given cost of 18 dolls = ₹630

$\therefore$ $\frac{18}{630}=k---\left(i\right)$

Let $x$ be the number of dolls can be bought for ₹455.

$\therefore$ $\frac{x}{455}=k---\left(ii\right)$

Equating (i) and (ii)

We get $\frac{18}{630}=\frac{x}{455}$

$\Rightarrow x=\frac{455\times 18}{630}=13$

$\therefore$ Number of dolls can be bought for ₹455 = 13