first off, let's convert the mixed fraction to improper fraction and then proceed, let's notice that by PEMDAS or order of operations, the multiplication is done first, and then any sums.
![\stackrel{mixed}{1\frac{7}{8}}\implies \cfrac{1\cdot 8+7}{8}\implies \stackrel{improper}{\cfrac{15}{8}} \\\\[-0.35em] ~\dotfill\\\\ -\cfrac{3}{4}~~ + ~~\cfrac{15}{8} \div \cfrac{1}{2}\implies -\cfrac{3}{4}~~ + ~~\cfrac{15}{8} \cdot \cfrac{2}{1}\implies -\cfrac{3}{4}~~ + ~~\cfrac{15}{4} \\\\\\ \cfrac{-3+15}{4}\implies \cfrac{12}{4}\implies 3](https://tex.z-dn.net/?f=%5Cstackrel%7Bmixed%7D%7B1%5Cfrac%7B7%7D%7B8%7D%7D%5Cimplies%20%5Ccfrac%7B1%5Ccdot%208%2B7%7D%7B8%7D%5Cimplies%20%5Cstackrel%7Bimproper%7D%7B%5Ccfrac%7B15%7D%7B8%7D%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20-%5Ccfrac%7B3%7D%7B4%7D~~%20%2B%20~~%5Ccfrac%7B15%7D%7B8%7D%20%5Cdiv%20%5Ccfrac%7B1%7D%7B2%7D%5Cimplies%20-%5Ccfrac%7B3%7D%7B4%7D~~%20%2B%20~~%5Ccfrac%7B15%7D%7B8%7D%20%5Ccdot%20%5Ccfrac%7B2%7D%7B1%7D%5Cimplies%20-%5Ccfrac%7B3%7D%7B4%7D~~%20%2B%20~~%5Ccfrac%7B15%7D%7B4%7D%20%5C%5C%5C%5C%5C%5C%20%5Ccfrac%7B-3%2B15%7D%7B4%7D%5Cimplies%20%5Ccfrac%7B12%7D%7B4%7D%5Cimplies%203)
700/10 equals 70, so the answer is 70.
1. A factory worker in Cambodia makes 320,000 Cambodian Riels per month. If 1 U.S. dollar equals 4000 Cambodian Riels, how much does the factory worker make in U.S. in dollars per year?
For this case we must first take the amount $ per month.
We have then:
1 $ ---> 4000
x = ----> 320000
Solving for x we have
x = (320000/4000) * (1) = $ 80 / month
We have then that 1 year two 12 months
($ 80 / month) * (12 months / 1 year) = $ 960 / year
Answer
the factory worker make 960 U.S. in dollars per year
2. People in Japan on average eat 3 ounces of fish per day. How many pounds of fish is this per week?
For this case, the first thing you should know is that a week has 7 days.
We can make a rule of three to find the number of ounces per week
3 ---> 1
x = ----> 7
x = (7/1) * (3) = 21ounces / week
Then, we should do the conversion of ounces to pounds
1 oz = 0.0625 pounds
Thus,
(21ounces / week) * (0.0625 punds / 1 ounce) = 1.3125 pounds / week
answer
3 ounces of fish per day is 1.3125 pounds / week
3. The town of Lloró, Colombia has an average yearly rainfall of 500 inches. On average, how many centimeters of rain does the town get each day?
The first thing you should know in this case are the following conversions:
1 year = 365 days
1 inch = 2.54 centimeters
We have the annual average rainfall is
500 (inches / year)
Making the conversion we have
500 (inches / year) * (2.54) (centimeters / inches) * (1/365) (year / days) =
3.45 (centimeters / days)
Answer
the town get each day 3.45 (centimeters / days)
4. The average American student is in class for 330 min / day. How many hours / day is this? Part b) How many sec / day?
The first thing you should know for this case are the following conversions
1 hour = 60 minutes
1 minute = 60 seconds.
Making the right conversions we have
330 (min / day) * (1/60) (hour / minutes) = 5.5hours / day
On the other hand we have
330 (min / day) * (60/1) (seconds / minutes) = 19800 sec / day
answer
330 (min / day) = 5.5hours / day
330 (min / day) = 19800 sec / day
We need to leave m alone on the right hand side, so let's move everything else to the left hand side.
First of all, we can subtract b from both sides to get
Now, we can divide both sides by c to get
And so we solved the expression for m, because we have written an expression in the form 
, where the right hand side doesn't depend on m.
