Question

jenny is 6b years old. Her brother is half her age and her sister is 4 years older than jenny. What is the average age of the three siblings in terms of b?

Answer 1

5b + 4/3

Explanation:

So if Jenny is 6b and her brother is half that he must be 3b. If her sister is four years older than her then she must be 6b + 4. To find the mean (or average) you add all the numbers and then divide by how ever many things you added together, so you would do:

Average = (6b+3b+6b+4) ÷ 3

= (15b+4) ÷ 3

= 5b + 4/3