1. A man's regular pay is Taka 30 per hour up to 40 hours. Overtime is twice the payment for regular time. If he was paid Taka 1680, how many hours overtime did he work ?
2. In a group of 60 people like Coca cola and 42 people like Pepsi Cola. Each person likes at least one of the two drinks. How many of these people like both Coca Cola and Pepsi Cola ?
4. ................. controls the functioning of the computer system as well as provides users the means to interact with the computer.