Two tankers contain 550 litres and 310 litres of petrol respectively. A container with maximum capacity is used which can measure the petrol of either tanker in exact number of litres. How many containers of petrol are there in the first tanker.

Three years ago Sander was five times older than his daughter. After three years, Sander will be 9 years more than two times the age of his daughter. Find the present age of Sander and his daughter.

Trains A and B leave station at the same time. Train A travels in West direction and train B travels in North direction. Train A is 0.5 km/hour slower than train B. After 2 hours, trains are 29 km apart. Find the speed of both trains.

From among a group of 4 men, 5 women and 5 children, 3 individuals are selected randomly. What is the probability that exactly 2 among the chosen are children?

Coin A is flipped 3 times and coin B is flipped 4 times. What is the probability that the number of heads obtained from flipping the two coins is the same?