A red horse and a black horse raced on a 1-mile-long circular racetrack. The red horse completed the race in 120 seconds, and the black horse completed the race in 150 seconds. Which choice correctly describes the speed of the horses?

The speed of red horse = 44 feet per second and the speed of black horse = 35.2 feet per second.

Step-by-step explanation:

Given: A red horse and a black horse raced on a 1-mile-long circular racetrack.

Time taken by red horse = 120 seconds

Time taken by black horse = 150 seconds

Speed =

So, speed of red horse =

Since 1 mile = 5280 feet

Speed of red horse =

Similarly,

Speed of black horse =

Hence, the speed of red horse = 44 feet per second and the speed of black horse = 35.2 feet per second.

answer: c, the green line

step-by-step explanation:

there is no black line, eliminate b.

simple interest implies periodic payments, but the red line shows no payments, eliminate d.

simple interest has equal payments. if paid say every day, the graph is about a straight line (actually a stairstep).

the yellow line is not straight, eliminate a.

check: the green line is straight, answer is c.

simple interest with positive interest rate gives a straight line sloping up to the right. green line:

g(t) = $100 + ($200-$100) ÷ (20 years) × (t years)

= $100 + (4%/year) × ($100)(t years)

incidentally, the yellow line curving upward represents continuously compounded interest

y = $100 × 2^(t years / (14 assuming the yellow line hits $200 at 14 years. 2^0 is 1, so y(0) = $100; 2^(14/14) is 2, so y(14) = $200.