A list of 18 numbers has an average of 332. When two numbers are deleted from the list, the average of the remaining numbers is 320.
- What is the sum of 18 numbers?
- What is the bigger number between the two numbers that have been deleted given that the difference between the two numbers is 4?
(a)
Sum of the 18 numbers
= 18 x 332
= 5976
(b)
Remaining numbers
= 18 - 2
= 16
Sum of the remaining numbers
= 320 x 16
= 5120
Sum of the two numbers
= 5976 - 5120
= 856
Smaller number = 1 u
Bigger number = 1 u + 4
Total = 1 u + 1 u + 4 = 2 u + 4
2 u + 4 = 856
2 u = 856 - 4
2 u = 852
1 u = 852 ÷ 2 = 426
Bigger number
= 1 u + 4
= 426 + 4
= 430
Answer(s): (a) 5976; (b) 430