The average of 10 numbers is 20 and that of other 30 numbers is 40. What is the average of all the numbers?
Given,
The average of 10 numbers = 20
⇒ Sum of 10 numbers = 20 × 10 = 200
The average of other 30 numbers = 40
⇒ Sum of other 30 numbers = 40 × 30 = 1200
Sum of all 40 numbers = 200 + 1200 = 1400
∴ Average of all 40 numbers = 1400/40 = 35
Hence, Average of 40 numbers = 35