How do you calculate distance if you have the time and rate?
A
Practice makes perfect
When calculating distance, rate, or time, we usually use the following formula.
distance=rate*time
⇓
d=r* t
In this exercise, we are given a table of the distances Josh traveled in miles and the time in hours it took for him to travel those distances.
Suppose we ignore the given answers for a moment. In that case, we should be able to calculate Josh's rate and then substitute it back into the formula to find our answer. First, let's isolate the rate r.
Now we can substitute the given values into this equation to determine Josh's rate.
(t,d)
Substitute
Simplify
( 2, 60)
r=60/2
r=30
( 5, 150)
r=150/5
r=30
( 7, 210)
r=210/7
r=30
( 8, 240)
r=240/8
r=30
Josh travels at a speed of 30 miles per hour. Substituting this into the formula, we get the equation representing the relationship between d and t.
d= 30t
Therefore, the answer is choice A.
Alternative Solution
Process of Elimination
We can also find the answer using the process of elimination. Let's recall the Distance Formula.
Distance=rate*time
⇓
d=r* t
Observing the given choices, we can immediately dismiss options C and D because they do not match the format of the Distance Formula.
C )& d=30+t
D )& t=d+30
B can also be dismissed because of the placement of the variables d and t. B ) & t=30d
We can isolate t on the left-hand side of the Distance Formula to double check our work.
