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:49/4
Step-by-step explanation:
Improper fraction
Answer:
12
Step-by-step explanation:
First figure the ratio of the real building to the model which is 21 divide 3. So the ratio is 1:7, since we're finding the height of the model, we divide 7 by 84 which is 12
The answer is 4, 320, 000
explanation: the problem is asking what the population of city c is, and to do that you need to multiply city b times 2. therefore you do not need the population of city a, it is just there to confuse you
Answer:
im not sure because im not good at these question but ill let you know when i figure it o