Question

4. The average of a class of twenty boys is 15 years. If eight boys of 18 years average join the class.
Find the new average of the class ?​

Answer 1

Answer:

11.68

Step-by-step explanation:

Average of 20 boys = 15

= > (sum/20) = 15

= > sum = 15*20 = 300

Average of 8 boys = (sum/8)

= > 18 = sum/8

= > 18*8 = 144 = sum

Average of 20 + 18 boys:

= > (300 + 144)/(20 + 18):

= > (444)/38

= > 11.68