The average of five positive numbers is 308. The average of first two numbers is 482.5 and the average of last two numbers is 258.5. What is the third number?

Correct option is B

Average of five numbers = 308
Sum of five numbers = 308 × 5 = 1540
Sum of first two numbers = 482.5 ×2 = 965
Sum of last two numbers = 258.5 × 2 = 517
So, the third number = 1540 – 965 – 517 = 58