Question

A woman drove part of a 185 mi trip at 50 mi/h and the rest at 55 mi/h. Find the distance she traveled at 50 mi/h if her total driving time was 3 h and 30 min.

Answer 1

Let x hours be time she drove at 50mi/hr then (3.5-x) hours she drove at 55mi/hr....... Now,
Total distance travelled = 185 mi

Answer 2

Does it help?

Answer 3

wait no how do i solve?

Answer 4

Hope...this helps...))

Answer 5

the only thing i am confused about is how you get 180-y as the distance

Answer 6

we knw total distance is 180 so....if the first one travels y miles....then the next one would travel 180 - y

Answer 7

Did u get it...

Answer 8

isnt the total difference 185

Answer 9

yes....i am sorry i didnt notice

Answer 10

i hope..u understood wat i said

Answer 11

wait so far i got y= 55x -7.5
is that correct?

Answer 12

Let x hours be time she drove at 50mi/hr let the distance coverd During this time y

S = D/T = 50 * x = y -------- 1


CaseII

Time = 3.5 - x Distance = 180 - y Speed=55

S = D/T 55 (3.5 - x) = 185 - y

192.5 - 55x = 185- y

-55x + y = -12.5 ---------2


nw u have two equations and two unknown variable.....find x and y

Answer 13

i got -12.5 + 55x= 55x- 7.5

Answer 14

Total distance:
d = d1 + d2
= v1t + v2 ( 3.5 - t)
= 55t + 50 ( 3.5 - t)
@pepper0331 Do you understand until this part?

Answer 15

185 mi = 5t + 175 mi

Answer 16

Can you fill in the blanks now :
-> t = (185 - 175) / 5 = ....
Thus the distance d1: 55 * ....
d2: 50 * ....

Answer 17

Questions, comments ???

Answer 18

yeah. i got the part about (185-175)/5 which is 2. but what is 2?? and how do you solve the answer with it?

Answer 19

oh wait i just read the part above now let me solve

Answer 20

wait is the answer 100. i did d=rt so d=100

Answer 21

thanks so much!

Answer 22

Feel free to verify if the solution is unclear :)

Answer 23

@pepper0331 the distance d2 Is NOT 100 mi
Pay attention at: 55t + 50 ( 3.5 - t)
With t = 2 hrs, the distance d1 at 55 mi/h : 55 * 2 = 110 mi
the distance d2 at 50 mi/h : 50 ( 3.5 - 2 ) = 50 * 1.5 = 75 mi

Answer 24

oh thanks