Answer:
c is
Step-by-step explanation:
If 80% of C is 20, 40% of C is 10, 20% is half of that, so 5
20% x 5 = 100%
5 x 5 = 25
C = 25
It would help to first find the unit rate. We know that the plane flies 810 km per 1.5 hours. Divide by 1.5 on both sides:
810/1.5 = 540 km/hour
Then, multiply both the hour and the distance by 2:
540 * 2 = 1080 km/2 hours.
24 and 42, I got this by multiplying 5 and 2 then doing the same thing to 7 and adding the sums. I used this method to find the perimeter of 10 and 12 as well.
The standard form equation for a straight line is y=mx+b where m is the slope and b is the y intercept. Substitute your given information:
y= -3/7x+2 is the equation
25 kids in all
2xboys:3x girls
so the equation would be
2x+3x=25
solve,
5x=25
/5 /5
x=5
2x=10
3x=15
10 boys and 15 girls