Question

The average age of 10 children is 9 years 9 months . the average age of 9 children is 8 years 11 months. What is the age of the tenth child?​

Answer 1

Answer:

Average age of 10 children = 9 years 9 months

sum of ages of 10 children = 9×10+912×10

= 3904

Average age of 9 children = 8 years 11 months

sum of age of 9 children = 8×9+1112×9

= 3214

Age of 10th child = 3904−3214=694

= 17 years 3 months

Answer 2

Step-by-step explanation:

sum of ages of 10 children = 9×10+9/12 ×10 =390/4

sum of the ages 9 children =8×9+11/12×10= 321/4

age of 10th children =390/4 - 321/4 =69/4 = 17 years 3 months ..