Question

31. Average age of 7 family members is 75
years. But average age of 6 of them is 74
years 6 months. What is the age of the 7th
family member?
(a) 75.5
(b) 78
(C) 68
(d) 80​

Answer 1

Answer:

A. 75.5

Step-by-step explanation:

this is right answer

Answer 2

Answer:

b) 78

Step-by-step explanation:

avg = sum of all ages / no of members = sum / 7

sum/7= 75

sum= 75×7= 525 years

let the age of 7th member be x

average of 6 members is 74 years 6 months

(sum- x)/6= 74 years 6 months

(525-x)= 444 years 36 months = 447 years

36 months = 3 years

so

x = 525 - 447 = 78 years