Answer:
1. 8.85 quarts
2. 44.25%
Step-by-step explanation:
In 15 quarts of a solution with percentage of antifreeze = 35%
Amount of antifreeze = 35% × 15
= 0.35 × 15
= 5.25 quarts
that solution is mixed with 5 quarts of a solution with percentage of antifreeze = 72%
Amount of antifreeze = 72% × 5
= 0.72 × 5
= 3.6 quarts
Total amount of mixture = 15 quarts + 5 quarts = 20 quarts
1. Now we will calculate the total amount of antifreeze in the resulting mixture.
= 5.25 + 3.6 = 8.85 quarts
2. The percentage of the resulting mixture is antifreeze
= 
= 44.25%
1. total amount of antifreeze is 8.85 quarts
2. the percentage of antifreeze is 44.25%
1 cm = 20 km
so 3.5 cm would equal : 3.5 * 20 = 70 km <==
Answer:
12
Step-by-step explanation:
by Pythagoras theorem,
P²+B² =H²
5²+B²=13²
B²= 13²-5²
B²= 169-25
B²= 144
B=√144
B= 12
Answer:

Step-by-step explanation:
step 1
Find the slope
The formula to calculate the slope between two points is equal to

we have
the points (−1,12) and (1,2)
substitute



step 2
we know that
The equation of the line in slope intercept form is equl to

where
m is the slope
b is the y-intercept
we have


substitute in the linear equation and solve for b


therefore

<span>6 km × 1 hour/(b-4 km) = 12 km × (1 hour/(b+4 km)
6/(b-4) hours = 12/(b+4) hours
6(b+4) = 12(b-4)
6b + 24 = 12b - 48
72 = 6b
b = 12
The boat's speed in still water is 12 km/hour.</span>