# Mental Ability-Basic Arithmetic (NCO- Cyber Olympiad Class 7): Questions 40 - 44 of 122

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## Question number: 40

» Mental Ability » Basic Arithmetic

MCQ▾

### Question

The average age of 20 children in a class is 8 years. If the teacher’s age is included, the average age becomes 10 years. Find the teacher’s age.

### Choices

Choice (4) Response

a.

50

b.

42

c.

45

d.

35

## Question number: 41

» Mental Ability » Basic Arithmetic

MCQ▾

### Question

If the area of a triangle with base is equal to the surface area of a cube with length of edge , and then the altitude of the triangle is

### Choices

Choice (4) Response

a.

b.

a

c.

d.

## Question number: 42

» Mental Ability » Basic Arithmetic

MCQ▾

### Question

The ratio of the number of boys and girls in a college is 8: 9. If the percentage increase in the number of boys and girls were 20 % and 10 % respectively, what will be the new ratio?

### Choices

Choice (4) Response

a.

96: 99

b.

23: 24

c.

8: 9

d.

17: 18

## Question number: 43

» Mental Ability » Basic Arithmetic

MCQ▾

### Question

A cistern can be filled by two tapes A and B in 12 hours and 16 hours respectively. The full cistern can be emptied by a third tap C in 8 hours. If all the taps were turned on at the same time, in how much time will the empty cistern be filled up completely?

### Choices

Choice (4) Response

a.

36 hours

b.

40 hours

c.

24 hours

d.

48 hours

## Question number: 44

» Mental Ability » Basic Arithmetic

MCQ▾

### Question

If 20 men working 7 hours a day can do a piece of work in 10 days, in how days will 15 men working for 8 hours a day to do the same piece of work?

### Choices

Choice (4) Response

a.

11.66 days

b.

55 days

c.

30 days

d.

12 days

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