Question

David purchases 10 pens for $Rs150$ and William buys $7$ pens $Rs84$.Can you say who got pen cheaper?

Answer 1

By unitary Method:

Total number of pens purchased by David for $Rs150$ $=10$ pens

So, the cost of $1$ pen $=\frac{150}{10}=15Rs$

Also, the total number of pens purchased by Williams for $Rs84$ = $7$pens

So, the cost of $1$ pen will be $=\frac{84}{7}=Rs12$

Thus, we observed that the total number of pens purchased by William is cheaper than David.