Question

Rahul purchased $7$ dvds each of which costs $₹17$. He gave a five hundred rupee note to the shopkeeper. The amount returned to him is divisible by?

Answer 1

Given that Rahul purchased $7$ dvds

Cost of $1$ dvd $=₹17$

$\Rightarrow$Cost of $7$ dvds $=7\times 17=₹119$

He gave a five hundred rupee note to the shopkeeper.

Therefore, the amount the shopkeeper returned $=500–119=₹381$

Now

$381=3\times 127$

Here both $3$and $127$ are prime numbers.

Hence, the amount returned to him is divisible by both $3$ and $127$.