Question

Kiran drove from Tortula to Cactus, a distance of 250 mi. She increased her speed by 10 mi/h for

the 360-mi trip from Cactus to Dry Junction. If the total trip took 11 h, what was her speed from Tortula to Cactus?

Answer 1

Let x be Kiran's speed from Tortula to Cactus.

The time it took her to drive from Tortula to Cactus is 250/x.

The time it took her to drive from Cactus to Dry Junction is 360/(x+10).

The total time of the trip is 250/x + 360/(x+10) = 11.

Multiplying both sides of the equation by x(x+10), we get:

250x + 360 = 11x^2 + 110x

11x^2 - 140x + 360 = 0

Factoring the equation, we get:

(x-12)(x-30) = 0

Therefore, x = 12 or x = 30.

Since x is the speed, it must be a positive number. Therefore, x = 12.

Kiran's speed from Tortula to Cactus was 12 mph.

Explanation: