Speed was increased 20% to 48 mph. What was the speed before the increase

40 mph

Step-by-step explanation:

If the speed increased by 20%, now the speed is 120% of the original speed.

48 mph is 120%, so dividing by 6 will get 8 which is 20%.

If 8 is 20%, you can multiply it by 5 to get 40, which is 100%. This means 40 mph is the original speed.

Hope this helps!

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.