A list of 12 numbers has an average of 350. When two numbers are deleted from the list, the average of the remaining numbers is 319.
- What is the sum of 12 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 12 numbers
= 12 x 350
= 4200
(b)
Remaining numbers
= 12 - 2
= 10
Sum of the remaining numbers
= 319 x 10
= 3190
Sum of the two numbers
= 4200 - 3190
= 1010
Smaller number = 1 u
Bigger number = 1 u + 4
Total = 1 u + 1 u + 4 = 2 u + 4
2 u + 4 = 1010
2 u = 1010 - 4
2 u = 1006
1 u = 1006 ÷ 2 = 503
Bigger number
= 1 u + 4
= 503 + 4
= 507
Answer(s): (a) 4200; (b) 507