The average of a,b,c is 20 and that of b,c,d is 25, if d=30, then the value of a is-

The average weight of A B and C is 50 kg . if the average weight of A and B be 48 kg and that of B and C be 45 kg , then find the weight of B ?

The average monthly income of x and y is 5050. The average monthly income of y and z is 6250 and the average monthly income of x and z is 5200. The monthly income of x is?

What is the average of the first five prime numbers?

The average weight of 5 persons sitting in a boat is 38 kg. The average weight of the boat and the persons sitting in the boat is 52 kg. What is the weight of the boat?

The average of three numbers is 40. The first number is twice the second and the second one is thrice the third number. The difference between the largest and the smallest numbers is

Of the three numbers whose average is 60, the first is one-fourth of the sum of the whole number. The first number is: 

In a primary school 96 students are studying. Their average weight is 30 kg. If a student shift to another school the average weight is increased by 200 gm. Find the weight of the student who shifted from the school.