a2zinterviews

31.	Three years ago, the average age of A and B was 18 years. With C joining them, the average age becomes 22 years. How old is C now?
	A.  18 years
	B.  24 years
	C.  27 years
	D.  28 years

Solution

Present age of (A+B) = (18x2+3x2) years = 42 years. Present age of (A+B+C) = (22x3) years = 66 years. ∴ C's age = (66 - 42) years = 24 years.

32.	The average age of 35 students in a class is 16 years. The average age of 21 students is 14. What is the average age of remaining 14 students?
	A.  14 years
	B.  17 years
	C.  19 years
	D.  21 years

Solution

Sum of the ages of 14 students = (16 x 35) - (14 x 21) = 560 - 294. = 266. ∴ Required average = 266 / 14 = 19 years.

33.	The average weight of a class of 24 students is 35 kg. If the weight of the teacher be included, the average rises by 400 g. The weight of the teacher is
	A.  45 kg
	B.  50 kg
	C.  53 kg
	D.  55 kg

Solution

Weight of the teacher = (35.4 x 25 - 35 24)kg = 45 kg.