Runs in first 2 matches = 2 × 27 = 54. Runs in next 3 matches = 3 × 32 = 96. Total runs = 150. Average = 150 ÷ 5 = 29.5.
7473
The average score of a cricketer for 10 matches is 43.9 runs. If the average for the first six matches is 53, what is the average for the last four matches?
Total runs in 10 matches = 10 × 43.9 = 439. Runs in first six matches = 6 × 53 = 318. Remaining runs = 439 − 318 = 121. Average for last four matches = 121 ÷ 4 = 29.75.
7474
The average of 50 numbers is 38. If two numbers 45 and 55 are removed, what is the average of the remaining numbers?
For equal distances, average speed = (2uv) / (u + v). Substituting u = 40 and v = 24 gives (2 × 40 × 24) / (40 + 24) = 1920 / 64 = 30 km/hr.
7478
The average age of a family of 6 members is 22 years. If the youngest member is 7 years old, what was the average age of the family at the birth of the youngest member?
Current total age = 22 × 6 = 132. Seven years earlier, total age would be 132 − (6 × 7) = 90. At that time there were only 5 members because the youngest had just been born. Average = 90 ÷ 5 = 18.
7479
The average of 11 results is 50. If the average of the first 6 results is 49 and that of the last 6 results is 52, find the 6th result.
Sum of 11 results = 11 × 50 = 550. Sum of first 6 = 6 × 49 = 294. Sum of last 6 = 6 × 52 = 312. Adding both sums gives 606. Since the 6th value is counted twice, subtract the total: 606 − 550 = 56.
7480
A cricketer scores 72, 59, 18, 101, and 7 runs in five matches. What is his average score?
