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.
To get the result we just have to divide 3.4 liter by 0.4 liter.
3.4:0.4=8.5 - its our result.
To better undestand lets think that u have 4 piece of cake and 2 person. To know how much u can give each person u have to divide 4 piece by 2 person. Its similar situation here.
C, adding the rest of this sentence because it needs to be longer
Answer:
You each will pay $40.35
Step-by-step explanation:
First you take the total $134.50 and divide it by 4 which is you and your three friends.
This will give you 33.625 which is the amount each of you will pay without tip.
To find the tip you take 20% from $134.50 which will give you 26.9 and when you divide that by the four of you it will give you 6.725.
Then you take your amount 33.625 plus your tip 6.725 which will give you $40.35.
The total you all will pay will be $161.40 this is the total $134.50 plus the tip $26.90.
Hope this helped.