Comments by Lakshman Bhaiya

Three bells $P$, $Q$ and $R$ are rung periodically in a school. $P$ is rung every $20$ minutes; $Q$ is rung every $30$ minutes and $R$ is rung every $50$ minutes.If all t...

How many integers are there between $100$ and $1000$ all of whose digits are even?$60$$80$$100$$90$