# Maths GK Questions With Answers for Competitive Exams – Part 3

Maths Questions with answers for competitive exams is about GK questions of Mathematics for competitive exams. Here you can find out practice problems for competitive exams.

MATHS QUESTIONS WITH ANSWERS FOR COMPETITIVE EXAMS – Part 3.

1. If 3/8 part of a number is 60, then find the number?
2. Find the value of 1000 + 0.001?
3. If we subtract 5 from twice a number, you will get 15, find the number?
4. A: B = 2:3, B: C = 5:7 then A: C = ————–
5. Find the cost of fencing a rectangular garden of length 100m and breadth 80m at the rate of Rs 25 per metre.
6. Find the sum of all angles of a polygon of sides 15?
7. Find the odd one out: 31, 41, 51,61.
8. Find the difference between 10% of 50 and 12% of 100?
9. Find the next number: 0.75, 2.25, 6.75, ————–
10. HCF of two numbers is 6 and LCM is 144. If one number is 18, find the other number?

1. 160
[Explanation: Let the number be x
Given 3/8 of x = 60
3x = 60 x 8
x = 480/3 = 160]
2. 1000.001
3. 10
[Let the number be x
Given 2x – 5 = 15
2x = 15 + 5 = 20
x = 20/2 = 10]
4. 10:21
[Explanation: A/B = 2/3 X 5/5 = 10/15
B/C = 5/7 X 3/3 = 15/21
A/C = A/B X B/C = 10/15 X 15/21 = 10/21.
So A: C = 10: 21]
5. Rs 9000
[Explanation: Perimeter = 2 (l + b) = 2 (100 + 80) = 2 X 180 = 360m
Cost of fencing = 360 X 25 = 9000]
6. 2340 Degree
[Explanation: Sum of all angles of a polygon of n sides = (n – 2) 180
Here n = 15
Sum = (15 – 2) 180 = 13 X 180 = 2340 degree]
7. 51
[Explanation: 51 is a composite number, all other numbers given are prime numbers]
8. 7
[Explanation: 10% of 50 = 10 x 50/ 100 = 5
12% of 100 = 12 x 100/ 100 = 12
Difference = 12 – 5 = 7]
9. 20.25
[Explanation: 0.75 x 3 = 2.25
2.25 x 3 = 6.75
6.75 x 3 = 20.25]
10. 48
[Explanation: HCF x LCM = Product of 2 numbers
6 x 144 = 18x
x = 6 x 144/18 = 48.]