Question

Guys I need help!!


A woman drives 10 miles, then increases her speed by 10 miles per hour and drives another 25 miles. Find her original speed if she drives for 45 minutes.

Answer 1

45

Answer 2

Let the original speed be s mph.

10/s + 25/(s+10) = 45/60

Answer 3

speed = distance / time
distance = time * speed
time = distance / speed

Answer 4

@denizen
speed = distance upon time

and time = distance upon speed
let the original speed be x
then
10/x + 25/ (x+10) = 45/60

(10 ( x+10) + 25(x) ) / x (x+10) = 45/60

now just solve it and you would get a quadratic equation
which can be further solved to get the value of x

Answer 5

hey @gudden thanks for the help

one last question is the answer is 37.03

Answer 6

(10x + 100 + 25x )/ x^2 + 10x = 3 / 4
on cross multiplying we get
(35x + 100 )4 = 3 ( x^2 + 10x )
140x + 400 = 3x^2 + 30x
0 = 3x^2 -110x - 400


lets use quadratic equation
d= 130

x = (110 - 130)/ 6 = - 20 / 6 = - 3.33

x = (110 + 130)/ 6 = 40

and hence speed = 40 mph..

Answer 7

Thank you so much @gudden

Answer 8

ur welcome :D