A list of 15 numbers has an average of 330. When two numbers are deleted from the list, the average of the remaining numbers is 300.
- What is the sum of 15 numbers?
- What is the bigger number between the two numbers that have been deleted given that the difference between the two numbers is 2?
(a)
Sum of the 15 numbers
= 15 x 330
= 4950
(b)
Remaining numbers
= 15 - 2
= 13
Sum of the remaining numbers
= 300 x 13
= 3900
Sum of the two numbers
= 4950 - 3900
= 1050
Smaller number = 1 u
Bigger number = 1 u + 2
Total = 1 u + 1 u + 2 = 2 u + 2
2 u + 2 = 1050
2 u = 1050 - 2
2 u = 1048
1 u = 1048 ÷ 2 = 524
Bigger number
= 1 u + 2
= 524 + 2
= 526
Answer(s): (a) 4950; (b) 526