There is a set of 30 numbers. The average of first 10 numbers is equal to the…
2026
There is a set of 30 numbers. The average of first 10 numbers is equal to the average of last 20 numbers. What is the sum of last 20 numbers?
- A.
Twice the sum of the first ten numbers.
- B.
sum of first 10 numbers.
- C.
Twice the sum of the last ten numbers
- D.
Cannot be determined
Attempted by 1348 students.
Show answer & explanation
Correct answer: A
Average of first 10 numbers = average of last 20 numbers
(Sum of 10 numbers)/10 = (sum of 20 numbers)/20
Let sum of first 10 numbers as X
Let sum of last 20 numbers as Y
X/10 =Y/20
Y = 20*(X/10)
Y = 2 X
Hence sum of last 20 numbers is double the sum of first 10 numbers.