100+ Average Questions and Answers for SSC Exams - 1

Question: 1

In a class there are 32 boys and 28 girls. The average age of the boys in the class is 14 years and the average age of the girls in the class is 13 years. What is the average age of the whole class (rounded to two digits after decimal)?

(A) 13.42

(B) 13.50

(C) 13.53

(D) 13.62

Ans: C

Required average = $$({32 × 14 + 28 × 13}/ {32 + 28})$$ = $$({448 + 364} / {60})$$ = $${812}/{60}$$. = 13.53.

Question: 2

David obtained 76, 65, 82, 67 and 85 marks (out of 100) in English, Mathematics, Physics, Chemistry and Biology. What is his average marks?

(A) 67

(B) 75

(C) 85

(D) 90

Ans: B

Average marks = $${76 + 65 + 82 + 67 + 85} /{5}$$ = $${375} / {5}$$ = 75.

Question: 3

The marks of six boys in a group are 48, 59, 87, 37, 78 and 57. What are the average marks of all six boys?

(A) 51

(B) 61

(C) 71

(D) 81

Ans: B

Total marks of six boys = 48 + 59 + 87 + 37 + 78 + 57 = 366.

Required average = $${366}/{6}$$ = 61.

Question: 4

The average age of 3 children in a family is 20% of the average age of the father and the eldest child. The total age of the mother and the youngest child is 39 years. If the father’s age is 26 years, what is the age of the second child?

(A) 15 years

(B) 18 years

(C) 21 years

(D) Cannot be determined

Ans: D

Since the total or average age of all the family members is not given, the given data is inadequate. So, the age of second child cannot be determined.

Question: 5

The average height of 25 boys is 1.4 m. When 5 boys leave the group, then the average height increases by 0.15 m. What is the average height of the 5 boys who leave?

(A) 0.6 m

(B) 0.8 m

(C) 0.9 m

(D) 0.95 m

Ans: B

Sum of heights of the 5 boys = (25 × 1.4 – 20 × 1.55) m = 4m.

∴ Required average = $$({4}/{5})$$m = 0.8 m.

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