Math 2 question

Question

Consider the formula Distance = speed*time or D = st. Suppose you work 20 miles from your home.

1. How long would it take to get to work if you were able to travel at a speed of 30mph?
2. What about 40mph? 50mph?
3. What do you notice about the relationship between your speed and how long it takes to get to work?

Please explain!

Answer 1

For the first part we know that our distance is 20 miles (“you work 20 miles from your home”) and the speed is given as 30 mph. Since we have two of the three variables in the equation, we can solve for the final one— time.

D = st 20 miles = (30mph) t t = 2/3 hours or about 0.667 hours

For part two the same process would be followed:

D= st

20 miles = (40 mph) t

t = 1/2 hour or 0.5 hours

D = st

20 miles = (50mph) t

t = 2/5 hour or 0.4 hours

For the final part it is evident and makes sense logically that if your car is going faster, you will arrive to work in less time. The math in these solutions also proves this assertion.