Garret is partway through a 20-minute bike ride. It takes 4 minutes for him to go a kilometer. Suppose k is the number of kilometers Garret has already biked. The expression 4(5-k) describes the number of minutes Garret has left in his ride.

The way it is right now looks good.

Step-by-step explanation:

if it takes him 4 minutes to go one kilometer then the equation 4(5-k) which is minutes left is saying how many kilometers out of the total 5 are left multiplied  by the amount of time it takes to go one kilometer  

well there are two answers for that.

1: you need 120 ones then that will equal up to 120.

2: you could also do one 100 and 2 tens.

those are the answers that i have thought of.