61. The average age of the mother and her six children is 12 years which is reduced by 5 years if the age of the mother is excluded. How old is the mother?
a) 40 years
b) 42 years
c) 48 years
d) 50 years
62. The captain of a cricket team of 11 members is 26 years old and the wicket keeper is 3 years older. If the ages of these two are excluded, the average age of the reaming players is one year less than the average age of the whole team. What is the average age of the team?
a) 23 years
b) 24 years
c) 25 years
d) None of these
63. The average height of 25 years is 1.4 m. when 5 boys leave the group, then the averages height increases by 0.15m. What is the average height of the 5 boys who leave?
a) 0.8 m
b) 0.9 m
c) O.95 m
d) 1.05 m
64. The average weighty of 8 person’s increases by 2.5 kg when a new person comes is place of one of them weighing 65 kg. What might be the weight of the new person?
a) 76 kg
b) 76.5 kg
c) 85 kg
d) Data inadequate
e) None of these
65. The average weight of 45 students in a class is 52 kg. Five of them whose average weight is 48 kg leave the class and other 5 students whose average weighty is 54kg join the class. What is the new average weight (in kg) of the class?
a) 52 1/3
b) 52 1/2
c) 52 2/3
d) None of these
ANSWERS
61.B
62.D
63.A
64.C
65.C
SOLUTION
61. Age of the mother = (12 x 7 – 7 x 6) years = 42 years.
62. Let the average age of the hole team be x years.
11x – (26 + 29) = 9 ( x – 1) 11 x – 9x = 46 2x = 46 x = 23.
So, average age of the team is 23 years.
63. Sum of heights of the 5 boys = (25 x 1.4 – 20 x 1.55) m = 4m.
Required average = (4/5) = 0.8m.
64. Total weight increased = (8 x 2.5) kg = 20 kg
Weight of new person = (65 + 20) kg = 85 kg.
65. Sum of the weights of the students after replacement
= ([(52 x 45) – (48 x 5) + (54 x 5)] kg = 2370 kg.
New average = (2370 /45) kg = 53 2/3 kg.
No comments:
Post a Comment