Average Questions Answers
-
1. Average of all prime numbers between 30 to 50
- 37
- 37.8
- 39
- 39.8
Answer And Explanation
Answer: Option D
Explanation:
Prime numbers between 30 and 50 are:
31, 37, 41, 43, 47
Average of prime numbers between 30 to 50 will be
\begin{aligned}
(\frac{31+37+41+43+47}{5}) = \frac{199}{5} = 39.8
\end{aligned} -
2. Reeya obtained 65, 67, 76, 82 and 85 out of 100 in different subjects, What will be the average.
- 70
- 75
- 80
- 85
Answer And Explanation
Answer: Option B
Explanation:
\begin{aligned}
( \frac {65+67+76+82+85}{5} ) = 75
\end{aligned} -
3. Find the sum of first 30 natural numbers
- 470
- 468
- 465
- 463
Answer And Explanation
Answer: Option C
Explanation:
Sum of n natural numbers
\begin{aligned}
= \frac{n(n+1)}{2}
\end{aligned}
\begin{aligned}
= \frac{30(30+1)}{2} = \frac{30(31)}{2} = 465
\end{aligned} -
4. Find the average of first 10 multiples of 7
- 35.5
- 37.5
- 38.5
- 40.5
Answer And Explanation
Answer: Option C
Explanation:
\begin{aligned}
= \frac {7(1+2+3+...+10)}{10}
\end{aligned}
\begin{aligned}
= \frac {7(10(10+1))}{10 \times 2}
\end{aligned}
\begin{aligned}
= \frac {7(110)}{10 \times 2} = 38.5
\end{aligned} -
5. The average of four consecutive odd numbers is 24. Find the largest number.
- 25
- 27
- 29
- 31
Answer And Explanation
Answer: Option B
Explanation:
Let the numbers are x, x+2, x+4, x+6, then
\begin{aligned}
=> \frac{x+(x+2)+(x+4)+(x+6)}{4} = 24
\end{aligned}
\begin{aligned}
=> \frac{4x+12)}{4} = 24
\end{aligned}
\begin{aligned}
=> x+3 = 24 => x = 21
\end{aligned}
So largest number is 21 + 6 = 27 -
6. Average of 10 numbers is zero. At most how many numbers may be greater than zero
- 0
- 1
- 5
- 9
Answer And Explanation
Answer: Option D
-
7. Find the average of all numbers between 6 and 34 which are divisible by 5
- 15
- 20
- 25
- 30
Answer And Explanation
Answer: Option B
Explanation:
\begin{aligned}
Average = (\frac{10+15+20+25+30}{5}) = \frac{100}{5} =20
\end{aligned}