I think the answer would be 160 but I don't know
Answer:
C) 20 hours
Step-by-step explanation:
x = number of hours
A yard cleanup service charges a $380 fee plus $14 per hour.
380 + 14x
Another cleanup service charges a $260 fee plus $20 per hour.
260 + 20x
How long is a job for which the two companies' costs are the same?
380 + 14x = 260 + 20x
380 - 260 = 20x - 14x
120 = 6x
20 = x
To solve this problem, let us first assign variables. Let
us say that:
x = volume of 67% herbicide solution
y = volume of 46% herbicide solution
The total volume should be 42 liters therefore:
x + y = 42
x = 42 – y --> 1
The component mass balance on the pure herbicide would
be:
0.67 x + 0.46 y = 0.55 (42) --> 2
Substituting equation 1 to 2:
0.67 (42 – y) + 0.46 y = 23.1
28.14 – 0.67 y + 0.46 y = 23.1
- 0.21 y = - 5.04
y = 24 L
Calculating for x using equation 1:
x = 42 – 24
x = 18 L
Therefore we only need 18 L of the 67% herbicide
solution.
Answer:
A. 18 L
Answer:
Step-by-step explanation:
4/(2+4+8+2) = 4/16 = 1/4
