There are two examination rooms A and B. If 10 students are sent from A to B, then the number of students in each room is the same. If 20 candidates are sent from B to A then the number of students in A is double the number of students in B. What is the number of students in room A?

If m and n are whole numbers such that $m^n$ prime prime =121, then the value of (m - 1)^{(n + 1)}  is:

A brother and a sister share out their collection of 5,000 stamps in the ratio of 5 : 3. The brother then shares his stamps with two friends in the ratio of 3 : 1 : 1 keeping most for himself. How many stamps does each of his friends receive?

If the length of the two sides of a trapezoid are 4cm and 7cm and height of the trapezoid is 7cm, calculate the area of the trapezoid.

40% of the students of a class failed in statistics and 35% of students failed in computer studies. If the class size is 200 and 70 students failed in neither of the subjects, then how many students failed in both the subjects?