A family consists of two grandparents, two parents and three grandchildren. The
average age of the grandparents is 67 years, that of the parents is 35 years and that
of the grandchildren is 6 ears. What is the average age of the family?
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
remaining players is one year less than the average age of the whole team. What is
the average age of the team?
Let P, Q and R represent their respective monthly incomes. Then, we have:
P + Q = (5050 x 2) = 10100 .... (i)
Q + R = (6250 x 2) = 12500 .... (ii)
P + R = (5200 x 2) = 10400 .... (iii)
Adding (i), (ii) and (iii), we get: 2(P + Q + R) = 33000 or P + Q + R = 16500 .... (iv)
Subtracting (ii) from (iv), we get P = 4000
Sum of the present ages of husband, wife and child = (27 x 3 + 3 x 3) years = 90
Sum of the present ages of wife and child = (20 x 2 + 5 x 2) years = 50 years
Husband's present age = (90 - 50) years = 40 years
In Arum’s opinion, his weight is greater than 65 kg but less than 72 kg. His brother
doest not agree with Arum and he thinks that Arum’s weight is greater than 60 kg
but less than 70 kg. His mother's view is that his weight cannot be greater than 68
kg. If all are them are correct in their estimation, what is the average of different
probable weights of Arum?
Let Arun's weight by X kg.
According to Arun, 65 < X < 72
According to Arun's brother, 60 < X < 70
According to Arun's mother, X <= 68
The values satisfying all the above conditions are 66, 67 and 68
Required Average = [$66+67+68\over3$]=[$201\over3$]=67kg.