A list of 18 numbers has an average of 349. 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 6?
(a)
Sum of the 18 numbers
= 18 x 349
= 6282
(b)
Remaining numbers
= 18 - 2
= 16
Sum of the remaining numbers
= 320 x 16
= 5120
Sum of the two numbers
= 6282 - 5120
= 1162
Smaller number = 1 u
Bigger number = 1 u + 6
Total = 1 u + 1 u + 6 = 2 u + 6
2 u + 6 = 1162
2 u = 1162 - 6
2 u = 1156
1 u = 1156 ÷ 2 = 578
Bigger number
= 1 u + 6
= 578 + 6
= 584
Answer(s): (a) 6282; (b) 584