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 313.
- 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 1?
(a)
Sum of the 15 numbers
= 15 x 330
= 4950
(b)
Remaining numbers
= 15 - 2
= 13
Sum of the remaining numbers
= 313 x 13
= 4069
Sum of the two numbers
= 4950 - 4069
= 881
Smaller number = 1 u
Bigger number = 1 u + 1
Total = 1 u + 1 u + 1 = 2 u + 1
2 u + 1 = 881
2 u = 881 - 1
2 u = 880
1 u = 880 ÷ 2 = 440
Bigger number
= 1 u + 1
= 440 + 1
= 441
Answer(s): (a) 4950; (b) 441