# Simple Arithmetic & Mental Ability / Maths GK Questions

**Simple Arithmetic & Mental Ability/ Maths GK Questions is about some model questions that you can expect for competitive examinations. Here you can find out Maths GK questions for competitive examinations.**

**Simple Arithmetic & Mental Ability/ Maths GK QuestionsExpected Maths GK Questions for Competitive ExaminationsChoose the correct answer:**

- If 2/5 of a number is 526, find the number?

A. 2630

B. 1315

C. 1052 - 1000 + 0.001 = ———-

A. 1000.1

B. 1000.01

C. 1000.001 - Convert to decimals: 80%

A. 4/5

B. 3/5

C. 2/5 - Find the cost of fencing a rectangular garden of length 125m and breadth 75m, at the rate of Rs 25 per metre?

A. 5000

B. 10000

C. 15000 - Sum of all angles of a polygon with 10 sides is ——— degree.

A. 1800

B. 1440

C. 720 - Find the odd one out:

A. 8

B. 27

C. 63 - The angle between the hour hand and minute hand of a clock when the clock time is 1 pm?

A.30 degree

B.60 degree

C.90 degree - Average of first 5 odd numbers is?

A.4

B.5

C.6 - Ramu travelled 25m straight towards East. He turned left and travelled 15m straight. Then turned right and travelled 20m straight. Again he turned right and travelled 15 m straight. How far is he from the starting point?

A. 40m

B. 45 m

C. 50 m - If 60% of the students in a school are girls and number of boys is 1250, find the number of girls?

A. 1870

B. 3125

C. 750

**ANSWERS:**

- 1315
- 1000.001
- 4/5
- 10000
- 1440
- 63
- 30 degree
- 5
- 45m
- 1875

**EXPLANATION:**

- Let the number be x.

Given 2/5 of x = 526

x = (526 x 5)/2 = 1315 - 1000 + 0.001 = 1000.001
- 80% = 80/100 = 8/10 = 4/5
- Perimeter = 2 (l + b) = 2 (125 +75) = 2 x 200 = 400 m

Cost of fencing = 400 x 25 = 10000 rupees - The sum of angles of a polygon with n sides = (n – 2) x 180

(10 – 2) 180 = 8 x 180 = 1440 degree - 8 and 27 are perfect cubes.

63 is not a perfect cube - 30 degree
- First 5 odd numbers are 1, 3, 5, 7 and 9

Average = (1+ 3 + 5 + 7 + 9)/5 = 25/5 = 5 - 45m
- Given 60% are girls. So the remaining 40% are boys

Let the total number of students be x

Then 40% of x = 1250

i.e., x = (1250 x 100)/40 = 3125

So the number of boys = 3125 – 1250 = 1875