Number System
The sum of 8 consecutive odd numbers is 656. Also average of four consecutive even numbers is 87. What is the sum of the smallest odd number and second largest even number ?
Average of 8 consecutive odd numbers = 656/8 = 82∴ Fourth number = 82 - 1 = 81∴ First numbers = 75Average of 4 even numbers = 87∴ Second even number = 87 - 1 = 86Second largest even number = 88∴ Required sum = 75 + 88 = 163
Total balls = 5 + 4 + 4 = 13∴ n(S) = 13C3 = 2862 blue balls can be selected from 4 balls in 4C2 = 6 ways and the remaining one ball is to be selected from 9 balls in 9C1 = 9 ways ∴ n(E) = 6 x 9∴ P(E) = 6 x 9/286 = 27/143