Answer:
Expressing a number in a power of 2 means that you have to figure out how many times you should multiply 2 by itself so the product will be that number.
The number is expressed as 2^n
For example:
Express 16 as a power of 2:
To get 16, you have to multiply 2 by 4 times.
2 × 2 × 2 × 2 = 16
16 = 2^4
Then the answer is 2^4
Okay, so he started out with 45 lbs.
Let's make 40% into a decimal.
40%= .4
I would multiply .4 to 45.
18.
Add 18 to 45 to get the answer.
The original weight of his bag was 63 pounds.

Step-by-step explanation:
The amount of time from 10pm to 7am is 9 hours. However, the time indicated is 7:10am. Since there are 60 minutes in an hour, 10 min is equal to 1/6 of an hour. Therefore, the total time that the water level of the pool decreased is
hours or
hours. To find the rate at which the water level decreased, we divide the change in the water (in inches) by the time it took to reach that level. So we write
rate of change 



21ft in yards equals 7 yards I hoped this helped!
220/400 = 55%
100%- 55% = 45%
there were 45% more girls than there were boys.