Answer:
17. C
18.G
Step-by-step explanation:
17. According to the question, gravel is 4/13 of the total asphalt substance. One parking lot has 260 tons of asphalt. So this means there is 80 tons of gravel because 260 times 4/13=80. We need to find the tons of gravel if we made 3 parking lot. This means 3 parking lot is the same as 780. So we can just find the measure of gravel by multiplying
4/13 by 780.
[tex] \frac{4}{13} \times 780 = 240[/tex]
So there is 240 tons of gravel. C is the answer.
18. Set up system of equations.
[tex]a + b + c = 110[/tex]
The ratio of a to c is 1:7 and the ratio of b to c is 3:7. Using this information,
- C is 7 times more than A.
- A is 3 times less than B
Using this info, we can make alternate equations
[tex]c = 7a[/tex]
[tex]b = 3a[/tex]
Subsitue this into the original equation,
[tex]a + 7a + 3a = 110[/tex]
[tex]11a = 110[/tex]
[tex]a = 10[/tex]
We need to find c, c is 7 times more than a so c is
[tex]c = 10 \times 7 = 70[/tex]
