SOLUTION: Kirk could drive 300 miles in twice the time it took Spock to drive 240 miles. The speed of Spock was 30 mph greater than that of Kirk. What were the speed and times of both?

Question 1143969: Kirk could drive 300 miles in twice the time it took Spock to drive 240 miles. The speed of Spock was 30 mph greater than that of Kirk. What were the speed and times of both?
Found 2 solutions by ikleyn, Alan3354:
Answer by ikleyn(52847) (Show Source): You can put this solution on YOUR website!
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Let x be the Kirk' speed, in miles per hour. Then the Spock' speed is (x+30) mph. The time for Kirk is hours. The time for Spock is mph. The time equation is = . From this equation, 300*(x+30) = 480x, 300x + 9000 = 480x 9000 = 480x - 300x 9000 = 180x x = = 50. ANSWER. Kirk' speed is 50 mph; Spock' speed is 50+30 = 80 mph. Kirk's time is = 6 hours; Spock' speed is = 3 hours.

Solved.

Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
Kirk could drive 300 miles in twice the time it took Spock to drive 240 miles. The speed of Spock was 30 mph greater than that of Kirk. What were the speed and times of both?
==========================
K = Kirk's speed
S = Spock's speed = (K+30)
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t = Spock's time to go 240 miles
2t = Kirk's time to go 300 miles
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150/K = 240/S = 240/(K+30)
Invert
K/150 = (K+30)/240
K/5 = (K+30)/8
8K = 5K+150
K = 50 mi/hr
S = 80 mi/hr

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