Arithmetic

Ram checks his purse and finds that he can buy an apple and three oranges or two apples for the money he has. From the same shop, Bheem buys two apples and two oranges for Rs 16. How much should I pay when I buy three apples and two oranges from the same shop?

There are 20 cities in a country. Each pair of cities is connected by an air route. How many air routes are there?

In a garden there are two plants. One plant is 44cm tall and the other is 80 cm tall. The first plant grows 3cm in every 2 months and the second 5 cm in every 6 months. The number of months after which the two plants will have equal height is _______.