Question

Ruby bought 5 toys for herself for Rs 350. She then bought 4 more toys for her baby brother. How much did the toys cost in total?

• A. Rs 450
• B. Rs 280
• C. Rs 630
• D. Rs 700

Answer 1

The correct option is C Rs 630

If the number of toys bought by Ruby increases, the total cost also increases.
$\therefore$ This is a case of direct proportion.

Ruby bought 5 toys for Rs 350. If she buys 4 more toys, then the total number of toys bought will be 9.
Using the formula for direct proportion,
$\frac{CostofToys}{NumberofToys}=constant$
$\Rightarrow \frac{350}{5}=\frac{Costof9Toys}{9}$
$\therefore Costof9Toys=70\times 9=Rs630$.