2
Q:

# The average of the first four numbers is three times the fifth number. If the average of all the five numbers is 85.8, then the fifth number is:

 A) 33 B) 34 C) 39 D) 29

Explanation:

Let the fifth number be x.
The average of the first four numbers = 3x
Sum of all the first four numbers = 3x = 12x
The average of all the five numbers = 85.8
Sum of all the five numbers = 85.8 5 = 429
Sum of all the first four numbers + 5th number = 429
12x + x = 429
x = 429/13 = 33
The 5th number is 33.

Q:

The average monthly expenditure of a family was ₹18,600 during the first three months, ₹21,750 during the next four months and ₹22,840 during the last five months of a year. If the total savings during the year was ₹1,43,020, then the average monthly income(in₹) of the family was

 A) 32,225 B) 34,115 C) 35,333 D) 33,335

Explanation:

2 172
Q:

The average of 40 numbers is 36. The average of the first 25 numbers is 31 and the average of last 16 numbers is 43. Find the 25th number.

 A) 21 B) 23 C) 24 D) 22

Explanation:

0 55
Q:

30 people went to a restaurant for a dinner party. 20 of them paid ₹880 each and each of the rest of them paid ₹110 more than the average of the total expenses. What was the total expense (in ₹) for the dinner?

 A) 27,840 B) 29,360 C) 28,050 D) 24,580

Explanation:

0 1160
Q:

There are three groups G1, G2 and G3 in a College with 20, 40 and 60 students respectively. The average marks obtained by groups G1, G2 and G3 are 50%, 60% and 70% respectively. Find the average marks of the entire college?

 A) 60% B) 63% C) 62% D) 61%

Explanation:

0 148
Q:

The ratio of the average ages of three people and the other two in a group of five people is 9 : 7. If the difference of their averages is 12, then find out the average age of all 5 people?

 A) 64.8 B) 46.8 C) 49.2 D) 48.4

Explanation:

1 129
Q:

The average of twelve numbers is 55.5. The average of the first four numbers is 53.4 and that of the next four numbers is 54.6. The 10th number is greater than the 9th number by 3 but lesser than the 11th and 12th numbers by 2 and 3, respectively. What is the average of the 10th and the 12th numbers ?

 A) 59.5 B) 58 C) 57.5 D) 56

Explanation:

0 109
Q:

The average weight of 30 persons of group A is 3 kg more than the average weight of 25 persons of group B. The average weight of 25 persons of group is 2.5 kg more than the average weight of 20 persons of group C. If the total weight of 30 persons of group A is 1725 kg, then what will be the average weight of the persons of group A and group C taken together (in kg)?

 A) 55.3 B) 55.4 C) 55.1 D) 55

Explanation:

0 90
Q:

The average of 9 numbers is 40. If the average of the first five numbers is 38 and that of the last five is 50, then what is the fifth number?

 A) 90 B) 84 C) 78 D) 80