# Number System Aptitude Questions and Answers:

#### Overview:

 Questions and Answers Type: MCQ (Multiple Choice Questions). Main Topic: Quantitative Aptitude. Quantitative Aptitude Sub-topic: Number System Aptitude Questions and Answers. Number of Questions: 10 Questions with Solutions.

1. If the sum of four consecutive even numbers is 172. Find the smallest of the numbers?

1. 46
2. 44
3. 42
4. 40

Answer: (d) 40

Solution: Let four consecutive even numbers are x, (x + 2), (x + 4), and (x + 6) then after adding these numbers $$4x + 12 = 172$$ $$4x = 172 - 12$$ $$4x = 160$$ $$x = 40$$ the four consecutive even numbers will be $$x = 40$$ $$x + 2 = 42$$ $$x + 4 = 44$$ $$x + 6 = 46$$ Hence the smallest number is 40.

1. If the sum of three consecutive odd numbers is 147. Find the second smallest number?

1. 45
2. 47
3. 49
4. 41

Answer: (c) 49

Solution: Let three consecutive odd numbers are x, (x + 2), and (x + 4) then after adding these numbers $$3x + 6 = 147$$ $$3x = 147 - 6$$ $$3x = 141$$ $$x = 47$$ the three consecutive odd numbers will be $$x = 47$$ $$x + 2 = 49$$ $$x + 4 = 51$$ Hence the second smallest number is 49.

1. If a person drinks 77 cups of coffee per week, find how many cups of coffee that person drank for the months of January, February, and March in the year 2020?

1. 1000
2. 1001
3. 1010
4. 1011

Answer: (b) 1001

Solution: The total number of days in the months January, February, and March 2020 $$31 + 29 + 31 = 91 \ days$$ Total numbers of weeks in 91 days $$\frac{91}{7} = 13 \ weeks$$ The person drinks 77 cups of coffee in one week, hence the number of cups of coffee that person has drunk in 13 weeks $$13 \times 77 = 1001$$

1. If the sum of three consecutive odd numbers is 51 then find the sum of the set of next three consecutive numbers?

1. 64
2. 66
3. 69
4. 71

Answer: (c) 69

Solution: Let three consecutive odd numbers are x, (x + 2), and (x + 4) then after adding these numbers $$3x + 6 = 51$$ $$3x = 51 - 6$$ $$3x = 45$$ $$x = 15$$ Now the three consecutive odd numbers will be $$x = 15$$ $$x + 2 = 17$$ $$x + 4 = 19$$ Hence the next set of consecutive odd numbers will be 21, 23, 25. The sum of the next three consecutive numbers $$21 + 23 + 25 = 69$$

1. The difference between the two numbers is 15 and the difference between their squares is 75 then find the smaller number?

1. 5
2. -5
3. 10
4. -10

Answer: (b) -5

Solution: Let the larger number is x and the smaller number is y then $$x + y = 15.....(1)$$ $$x^2 + y^2 = 75$$ $$(x + y) \ (x - y) = 75$$ by putting the value of (x - y) from equation (1) $$(x + y) = \frac{75}{15}$$ $$x + y = 5.....(2)$$ by adding equations (1) and (2) $$x - y + x + y = 15 + 5$$ $$2x = 20$$ $$x = 10$$ by putting the value of x in equation (1) $$10 - y = 15$$ $$y = 10 - 15$$ $$y = -5$$ Hence the smaller number is -5 and the larger number is 10.