Use the left and right triangles. (the two smaller ones -- ACD and BCD)
By similar triangles ACD is similar to BCD
on the left AD/CD is one ratio
On the right CD/DB is the other. These two ratios are equal because they are corresponding parts.
AD / CD = CD / DB
AD = 3
DB = 12
CD = ??
Substitute.
3/CD = CD/12 Cross multiply
36 = CD^2
sqrt(36) = sqrt(CD^2)
CD = 6 <<<<==== Answer.
A <<<<====Answer.
So, first, to make things easier, you should convert these mixed fractions into improper fractions so it's easier to deal with later. The improper fractions will be 51/10 divided by 32/5.
Since you're are dividing fractions, there is a rule when dividing fractions, you have to multiply the number by the reciprocal, meaning the second fraction needs to be flipped and the divide signs will turn into a multiply sign. It will be:
51/10 times 5/32
This is the time where you simply where you can:
51/2 times 1/32
After simplifying, you times the numerator together (the top number of the fraction) and the denominator (the bottom number of the fraction).
=51/64
Y = 6, z = 2
~Hope this helped!~
(The first page is the beginning of the equation, and the next page is the ending)
It should be for 5 hours if $30 is what they started with
The answer is: c
Explination 30-9=21