A list of 13 numbers has an average of 331. When two numbers are deleted from the list, the average of the remaining numbers is 311.
- What is the sum of 13 numbers?
- What is the bigger number between the two numbers that have been deleted given that the difference between the two numbers is 2?
(a)
Sum of the 13 numbers
= 13 x 331
= 4303
(b)
Remaining numbers
= 13 - 2
= 11
Sum of the remaining numbers
= 311 x 11
= 3421
Sum of the two numbers
= 4303 - 3421
= 882
Smaller number = 1 u
Bigger number = 1 u + 2
Total = 1 u + 1 u + 2 = 2 u + 2
2 u + 2 = 882
2 u = 882 - 2
2 u = 880
1 u = 880 ÷ 2 = 440
Bigger number
= 1 u + 2
= 440 + 2
= 442
Answer(s): (a) 4303; (b) 442