A: 73%
b: 2% / 2.3%
c: 17.6%
d: 241.5%
Answer:
179 mph
Step-by-step explanation:
Given: Average speed to cover 19 lap is 159 mph
Now, finding the speed of driver in 20th lap to attain 160 mph as an average speed.
Average Speed =
Considering x as speed in 20th lap.
⇒ 160 =
⇒ 160 =
Now, multiplying both side by 20.
⇒ 160 =
⇒ 3200 =
∴ x = 179 mph
179 mph should be the speed of driver in his 20th lap to attain an average speed of 160 mph.
Use substitution
Plug in -5x for y in the second equation
x + 3(-5x) = 28
x - 15x = 28
-14x = 28, x = -2
Now plug in -2 for x in first equation
Y = -5(-2) = 10
Solution: D. (-2, 10)
So ratios.
If you don't know what a ratio is, look it up.
the ratio for the 1st one is 15(shadow):12(actual height)
the next would be x:8
so 12/8 is 1.5
then you divide 15 by 1.5 to get 10
so the shadow should be 10ft long.