The average marks of a class of 30 students is 40 and that of another class of 50 students is 60. Find the average marks of all the students?
A. 50
B. 47.5
C. 59
D. 52.5
Basic Arithmetic
The average of 35 numbers is 25. If each number is multiplied by 5, find the new average?
A. 125
B. 134
C. 170
D. 98
The average salary of a person for the months of January, February, March and April is Rs.8000 and that for the months February, March, April and May is Rs.8500. If his salary for the month of May is Rs.6500, find his salary for the month of January?
A. 3000
B. 2500
C. 4500
D. 5000
The average of 10 numbers is 23. If each number is increased by 4, what will the new average?
A. 22
B. 27
C. 25
D. 29
The average of 11 results is 50, if the average of first six results is 49 and that of the last six is 52. Find the sixth result?
A. 46
B. 56
C. 34
D. 57
Find the average of the first 20 natural numbers?
A. 10
B. 11.5
C. 12
D. 10.5
The average of 13 numbers is 60. Average of the first 7 of them is 57 and that of the last 7 is 61. Find the 8th number?
A. 46
B. 32
C. 68
D. 51
A batsman makes a score of 64 runs in the 16th innings and thus increased his average by 3. Find his average after the 16th inning?
A. 17
B. 29
C. 18
D. 19
10 books are placed at random in a shelf. The probability that a pair of books will always be together is_________?
A. 1/10
B. 9/10
C. 1/5
D. 3/10
The probability of a lottery ticket being a prized ticket is 0.2. When 4 tickets are purchased, the probability of winning a prize on at least one ticket is__________?
A. 0.4869
B. 0.5904
C. 0.6234
D. 0.5834