46. The average of 8 numbers is 20. The average of first two numbers is 15 ½ and that of the next three is 21 ½. If the sixth number be less than the seventh and eighth numbers by 4 and 7 respectively, then the eighth number is:
a) 18
b) 22
c) 25
d) 27
47. If the arithmetic mean of seventy-five numbers is calculated, it is 35. If each number is increased by 5, then men of new numbers is:
a) 30
b) 40
c) 70
d) 90
48. The average of ten numbers is 7. If each number is multiplied by 12, then the average of the new set of numbers is:
a) 7
b) 19
c) 82
d) 84
49. Average of ten positive numbers is x. if each number is increased by 10%, then x: 9a) remains unchanged.
a) Remains unchanged
b) May decrease
c) May increase
d) Is increased by 10%
50. The mean of 50 observations was 36. It was found later that an observation 48 was wrongly taken as 23. Then corrected new mean is:
a) 35.2
b) 36.1
c) 36.5
d) 39.1
ANSWERS
