Average of 9 numbers is 20. If a number 30 is also included, then what will be the average of these 10 numbers?
Average of 9 numbers = 20
=> Total sum of the numbers = $$(20\times9)=180$$
New included number = 30
New average = $$\frac{180+30}{10}$$
= $$\frac{210}{10}=21$$
=> Ans - (B)
Create a FREE account and get: