Question

Yesterday, Tammy went on a bike ride. Her average speed was 8 miles per hour. Today, she went on another ride, this time averaging 12 miles per hour. In the two days, she biked for a combined total time of 10 hours. Let x be the number of hours she biked yesterday. Write an expression for the combined total number of miles she biked in the two days.

Answer 1

y=120-4x

Explanation:

Here we are given the average speed for Day 1 and Day 2 and the time of ride . We asked to Find an expression to determine the total distance travelled in two days.

Day 1 :

Avg Speed = 8 mph

Let the time for travelling = x hrs

Hence Distace Travelled D1= Speed x Time

D1=8x

Day 2 :

Avg Speed = 12 mph

Total time of travelling for two days is given as 10 hours . Hence the time of travelling for day 2 is

= (10-x) hrs

Hence Distance travelled in Day 2 D2 = speed x time

D2 = 12(10-x)

D2=120-12x

Total Distance travelled = D1 + D2

= 8x+120-12x

=120-4x

If the total distance travelled is denoted by y

The expression will be

y=120-4x