Math Question 1

Question

Kristina left the college traveling 16 mph. Then, 3 hours later, Maggie left traveling the same direction at 28 mph. How long until Maggie catches up with Kristina?

Answer 1

Hello, Bon,

Raymond has the correct answer. I had typed my answer, below, before I saw his reply. You might be able see something different, so here it is. The basic question is when will their distance travelled be equal? Let time be the X variable.

Bob

Speed(mph) Time Hours

K 16 X

M 28 X-3

Distance travelled equal to each other would be:

16X=28(X-3)

X=7 hours

16mph x 7 hr = 112 miles

28mphx 4 hr = 112 miles

They meet once again.

Answer 2

Set up the equation:

Where x is the number of hours kristina drives before maggie catches up

Where y is the number of hours maggie drives until she catches up to kristina, let y=x-3

We want to know the number hours of driven until both have driven the same number of miles...

16x=28y

16x=(x-3)28

16x=28x-84

-12x=-84

x=7

y=4

Check: 16*7 =4*28

112 = 112

it would take 4 hours for maggie to catch up to kristina

Answer 3

distance = rate of speed times time

d = rt

16T = 28(T-3) = 28T - 84

12T = 84

T = 84/12 = 7 hours for Kristina's driving time

T-3 = 7-3 = 4 hours for Maggie to catch up

16(7)= 112 = 28(4) = 112 miles for each