Question

Rohit bought 12 registers for Rs 156, find the cost of 7 such registers. (in Rs.)

Answer 1

Correct option is A. 91
Let the cost of $$7$$ registers be $$Rs.x$$

Register	$$12$$	$$7$$
Cost ( in Rs. )	$$156$$	$$x$$

If he buys less number of registers, the cost will also be less.

$$\therefore$$ It is a direct variation.

$$\Rightarrow$$ $$12:7=156:x$$

$$\Rightarrow$$ $$\dfrac{12}{7}=\dfrac{156}{x}$$

$$\Rightarrow$$ $$x=\dfrac{156\times 7}{12}$$

$$\Rightarrow$$ $$x=Rs.91$$

$$\therefore$$ The cost of $$7$$ such registers will be $$Rs.91.$$