Question

The average weight of Ajay's brother and sister is 39 kg. The average weight of all three of them is 30 kg. What is Ajay's weight in kilograms?

A)3
B)9
C)12
D)34.5



plz with all the steps.​

Answer 1

Answer:

Option C.12

Step-by-step explanation:

Given,

Avg weight of Ajay's brother and sister is 39 kgs

\\Avg = Sum of observations/No of Observations

Sum of observations = Avg×No of Observations\\

Sum of ages of Ajay's brother and sister is

39×2 = 78 kgs

Avg weight of all 3 members = 30 kgs

Sum of ages of 3 members = 30×3 = 90 kgs

Weight of Ajay = 90-78 = 12 kgs....

Hope it helps you........

Answer 2

Answer:

34.5 option D

Step-by-step explanation:

average = 30+39 =69÷2 = 34.5