A list of 15 numbers has an average of 332. When two numbers are deleted from the list, the average of the remaining numbers is 315.
- 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 5?
(a)
Sum of the 15 numbers
= 15 x 332
= 4980
(b)
Remaining numbers
= 15 - 2
= 13
Sum of the remaining numbers
= 315 x 13
= 4095
Sum of the two numbers
= 4980 - 4095
= 885
Smaller number = 1 u
Bigger number = 1 u + 5
Total = 1 u + 1 u + 5 = 2 u + 5
2 u + 5 = 885
2 u = 885 - 5
2 u = 880
1 u = 880 ÷ 2 = 440
Bigger number
= 1 u + 5
= 440 + 5
= 445
Answer(s): (a) 4980; (b) 445