Answer:
11 years old
Step-by-step explanation:
If four brothers have the average age 6, then the sum of their ages is

years.
Let x years be the age of sister. If four brothers and their sister have the average age 7, then

Multiply this equation by 5:

The sister is 11 years old.
Answer:
$22,500
Step-by-step explanation:
1/2 of $15000 is $7500, $7500+$15000 is $22,500
Answer:
20% of 160 is 32
Step-by-step explanation: