Answer:
The water level dropped
inch each hour
Step-by-step explanation:
- Between 10 P.M. and 7:45 A.M., the water level in a swimming pool
decreased by 13/16 inch
- Assuming that the water level decreased at a constant rate
- We need to find the drop each hour that means the unit rate of
decreased of the level of the water
- At first lets hind how many hours between 10 P.M. and 7:45 A.M.
∵ Between 10 P.M. and mid-night 2 hours
∵ Between mid-night and 7:45 A.M. 7 hours and 45 minutes
- Lets change 7 hours and 45 minutes to hours
∵ 1 hour = 60 minutes
∴ 45 minutes = 45 ÷ 60 =
hours
∴ 7 hours and 45 minutes =
hours
∴ The total hours between 10 P.M. and 7:45 A.M. = 2 +
hours
∴ The total hours between 10 P.M. and 7:45 A.M. = ![9\frac{3}{4}](https://tex.z-dn.net/?f=9%5Cfrac%7B3%7D%7B4%7D)
∵ The unit rate of decreased = The decreased level ÷ total hours
∵ The decreased level is
inche
∵ The total hours =
hours
- Lets change the mixed number
to improper fraction
∵
= ![\frac{(9*4)+3}{4}](https://tex.z-dn.net/?f=%5Cfrac%7B%289%2A4%29%2B3%7D%7B4%7D)
∴
= ![\frac{39}{4}](https://tex.z-dn.net/?f=%5Cfrac%7B39%7D%7B4%7D)
∵ The unit rate of decreased =
÷ ![\frac{39}{4}](https://tex.z-dn.net/?f=%5Cfrac%7B39%7D%7B4%7D)
- To solve the division of 2 fractions change the division sign to
multiplication sign and reciprocal the fraction after the division sign
∴ The unit rate of decreases =
×
∴ The unit rate of decreases =
inch per hour
The water level dropped
inch each hour