# Averages Quiz Set 001

### Question 1

The average number of visitors at a zoo on a Monday is 90, whereas it is 84 on other days of the week. What will be the average number of visitors in a 30-day month that begins on a Monday?

A

85.

B

86.

C

84.

D

83.

Soln.
Ans: a

The month begins on a Monday, so there will be 5 Mondays. The average = \${5 × 90 + 25 × 84}/30\$, which equals \${450 + 2100}/30\$ = 85.

### Question 2

A box contains 5 marbles each having a weight of 108 grams. The box also contains 25 marbles each having a weight of 72 grams. What is the average weight of all the marbles in the box?

A

78 grams.

B

79 grams.

C

77 grams.

D

76 grams.

Soln.
Ans: a

The weighted average = \${5 × 108 + 25 × 72}/30\$, which equals \${540 + 1800}/30\$ = 78.

### Question 3

A box contains 5 marbles each having a weight of 156 grams. The box also contains 25 marbles each having a weight of 114 grams. What is the average weight of all the marbles in the box?

A

121 grams.

B

122 grams.

C

120 grams.

D

119 grams.

Soln.
Ans: a

The weighted average = \${5 × 156 + 25 × 114}/30\$, which equals \${780 + 2850}/30\$ = 121.

### Question 4

In a cricket match of 50 overs a team has to chase a target of 425 runs. During the first 10 overs it has scored at the rate of 2.5 runs per over. What is the required run rate for the remaining 40 overs?

A

10.

B

11.

C

9.

D

8.

Soln.
Ans: a

The runs already scored = scoring rate × overs = \$2.5 × 10\$ = 25. Required number of runs = 425 - 25 = 400 in 50 - 10 = 40 overs. Required rate = 400/40 = 10.

### Question 5

Two of the 36 numbers are 28 and 58, If these two are excluded the average of the remaining 34 numbers is 1 more than the average of all the 36 numbers. What is the average of all the 36 numbers?

A

26.

B

27.

C

25.

D

28.

Soln.
Ans: a

Let the required average be x. Then \$36x - (28 + 58) = 34 × (x - 1).\$ which gives \$36x - 86 = 34 × (x - 1).\$ Solving for x we get x = 26.