A bag contains 25 white and some black balls. If the probability of drawing a black ball from the bag is thrice that of drawing a white ball, find the number of black balls in the bag.
The average age of a class of 17 girls is 12 years. If 3 new girls having average age of 8 years join the class, then the average age of the class becomes:
The average of three numbers P, Q and R is 1600. R is 75% more than P. The ratio of P and Q is 4:5 respectively. If R is 25% less than S, then find out ...
The average wage of a group of 20 labourers is Rs. 420. If 4 persons receiving average wage of Rs. 300 leave the group and 2 persons receiving average w...
In an examination the average marks of Rohit is 63. If he got 20 more marks in science and 28 more marks in maths then his average would have been 69. F...
The average of n numbers is 62. If each of 55% of the numbers is increased by 18 and each of the remaining numbers is decreased by 12, then the n...
The average of n numbers is 60. If each of 55% of the numbers is increased by 16 and each of the remaining numbers is decreased by 12, then the n...
The average expenditure of a man for the first 7 month is Rs.5000 and for the next 5 months is Rs.8000. If he saves 12000 in that year then find his ave...
The certain sum amounts to Rs11313.5 in 2(1/2) years at 12% p.a., interest compounded 10 months. The sum (in Rs) is:
Out of 4 numbers, the average of first 3 is 19 and last 3 is 20. If the last number is 21. Find the first number?
In an examination the average marks of Rohit is 55. If he got 15 more marks in science and 27 more marks in maths then his average would have been 62. F...
