Question

If $7\mathrm{kg}$ onions cost $140$ rupees, how much cost would we pay for $12\mathrm{kg}$ onions?

Answer 1

Use unitary method to evaluate the cost of required onions

Given,

$7\mathrm{kg}$ onions cost $\mathrm{Rs}140$

So, cost of $1\mathrm{kg}$ onion $=\frac{140}{7}=\mathrm{Rs}20$

$\therefore$Cost of $12\mathrm{kg}$ onions $=(20\times 12)=\mathrm{Rs}240$

Hence, the cost of $12\mathrm{kg}$ onions is $\mathrm{Rs}240$.