Two tankers contain 399 litres and 217 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.

Rehab is 6 years older than her friend Arwa. Rehab's father is twice as old as Rehab and Arwa is twice as old has her brother. The age of Rehab's father is 33 years more than the age of Arwa's brother. Find the ages of Rehab and Arwa.

A two digit number is such that the product of its digits is 48. If 18 is subtracted from the number, the digits interchange their places. Find the number.

In 2008, the meteorological office predicted the weathers completely right for the months of february and april, and completely wrong for all the other months. What is the probability that the forecast was right for a given day that year?

There are a total of 16 chocolates - 4 each in the flavors of grape, strawberry, mango and coffee. There are also 5 children. If each child is allowed to choose their own favorite flavor, what is the probability that all of them will get flavors of their choice?