CAT 2002QA Question 31

Time, Speed & DistanceEasy

On a 20 km tunnel connecting two cities A and B there are three gutters. The distance between gutter 1 and 2 is half the distance between gutter 2 and 3. The distance from city A to its nearest gutter, gutter 1 is equal to the distance of city B from gutter 3. On a particular day the hospital in city A receives information that an accident has happened at the third gutter. The victim can be saved only if an operation is started within 40 minutes. An ambulance started from city A at 30 km/hr and crossed the first gutter after 5 minutes. If the driver had doubled the speed after that, what is the maximum amount of time the doctor would get to attend the patient at the hospital? Assume 1 minute is elapsed for taking the patient into and out of the ambulance.

Answer & solution

Correct answer: 1.5 minutes

  • A

    4 minutes

  • B

    2.5 minutes

  • 1.5 minutes

  • D

    Patient died before reaching the hospital

Solution

As per the description,

AB = 20 km

AG1 = BG3

2G1G2 = G2G3

∴ x = 2.5 km

y + 2y = 20 − 2x

∴ y = 5 km

∴ Time to cover A to G3112+1560 = 20 min

∴ While coming back his speed is 60 km/hr.

∴ Time taken to cover the distance from G3 to A (i.e. 17.5 km) = 17.5 minutes

∴ Required time = 20 + 17.5 + 1 = 38.5 minutes

∴ The doctor will have 1.5 minutes to attend the patient.

Hence, option (c).

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CAT 2002 QA Q31: On a 20 km tunnel connecting two cities A and B there are three gutters. The distance between gutter 1 and 2 i — Solution | TheCATExam