Q completes a journey in 33 hours. She travels first half of the journey at the rate of 30 kmph and second half at the rate of 36 kmph. Find the total distance of the entire journey? (in km)

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UP Police SI (दरोगा) Official PYP (Held On: 20 Nov 2021 Shift 1)

Answer 1

Given:

Q completes a journey in 33 hours.

First half of the journey speed = 30 kmph

Second half of the journey speed = 36 kmph

Formula used:

Total time = (Distance/Speed for first half) + (Distance/Speed for second half)

Let total distance = D, so first half distance = D/2

Calculations:

Total time = 33 hours

⇒ \(\dfrac{D/2}{30} + \dfrac{D/2}{36} = 33\)

⇒ \(\dfrac{D}{60} + \dfrac{D}{72} = 33\)

⇒ \(\dfrac{6D + 5D}{360}= 33\)

⇒ \(\dfrac{11D}{360} = 33\)

⇒ D = 3 × 360

⇒ D = 1080 km

∴ The correct answer is option (4).