model 1 basic average questions Practice Questions Answers Test with Solutions & More Shortcuts

Question : 11

If the average of x and $1/x (x ≠ 0)$ is M, then the average of $x^2$ and $1/x^2$is :

a) $1-M^2$

b) $1-2M$

c) $2M^2-1$

d) $2M^2+1$

Question : 12

If the average of m numbers is $n^2$ and that of n numbers is $m^2$, then average of (m + n) numbers is

a) $m/n$

b) m+n

c) mn

d) m-n

Question : 13

Numbers of boys and girls are ‘x’ and ‘y’ respectively. Ages of a girl and a boy are ‘a’ years and ‘b’ years respectively. The average age (in years) of all boys and girls is

a) $\text"x+y"/\text"bx+ay"$

b) $\text"x+y"/\text"bx+ay"$

c) $\text"bx+ay"/\text"x+y"$

d) $\text"x+y"/\text"ax+by"$

Question : 14

Six friends have an average height of 167 cms. A boy with height 162 cm leaves the group. Find the new average height.

a) 169 cm

b) 167 cm

c) 166 cm

d) 168 cm

Question : 15 [SSC CGL Tier-I 2015]

The average weight of 15 oarsmen in a boat is increased by 1.6 kg when one of the crew, who weighs 42 kg is replaced by a new man. Find the weight of the new man (in kg).

a) 66

b) 43

c) 65

d) 67