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Jackie's watch loses two minutes every hour. Adam's watch gains one minute every hour. They both set their watches at the radio at 6:00 am, then start their journey to the airport. When they arrive (at the same time) their watches are twelve minutes apart. What is the real time they arrive at the airport?

2 Answers

4 votes
10:00 am If you look at the problem, you'll realize that Jackie's and Adam's watches diverge from each other by 3 minutes every hour of real time. So when they arrive, their watches differ by 12 minutes, so they've actually spend 12/3 = 4 hours travel time. Since they both started traveling at exactly 6:00 am using a common authoritative time standard (the radio). The current time is now 6:00 am + 4 hours = 10:00 am.
User Toufic Batache
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3 votes
Ratio of loss of tinme of Jackies warch to the gain of time of Adam's watch is 2 : 1

Let the number of hour ellapsed at the time they are twelve minutes apart be x, then

2x + x = 12

⇒ 3x = 12

⇒ x = 12 / 3 = 4

Thus, after 4 hours Jackie's watch has lost 8 minutes and Adam's watch has gained 4 minutes.

Therefore, the real time at the time they arrive at the airport is 10:00 am.
User Adomas Baliuka
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6.8k points