The average of 11 results is 30. If the average of the first five is 25 and that of the last five 28, then find the sixth result.
Answer & explanation
Correct answer: option 3
Total of 11 numbers = 11 × 30
Total of 1st five numbers = 5 × 25
Total of last five numbers = 5 × 28
ATQ,
(11 × 30) = (5 × 25) + 6th no. + (5 × 28)
5 (11 × 6) = 5 (28 + 25) + 6th no.
5(66) - 5 (53) = 6th no.
5(66 – 53) = 6th no.
6th no. = 5 × 13
6th no. = 65