JIPMAT 2024 (LR) - A watch which gains uniformly is 2 minutes slow at 10 AM on Wednesday and 2 1/2 minutes fast at 1 PM the following day. When will it show the correct time ? | PYQs + Solutions

JIPMAT 2024

Logical Reasoning

Clocks & Calendar

Medium

A watch which gains uniformly is 2 minutes slow at $10 \mathrm{AM}$ on Wednesday and $2 \frac{1}{2}$ minutes fast at 1 PM the following day. When will it show the correct time ?

10: 30

AM, Thursday

9: 15

PM, Wednesday

10: 30

AM, Wednesday

10 : 00

PM, Wednesday

Correct Option: 4

At 10 AM on Wednesday, watch is 2 minutes slow

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At 1 PM next day (27 hours later), watch is 2.5 minutes fast

Total time elapsed = 27 hours

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Total change in watch = 2 + 2.5 = 4.5 minutes gained

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Rate of gain =

\frac{4.5}{27}

minutes per hour =

\frac{1}{6}

minutes per hour

Time when watch shows correct time:

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Initial error = -2 minutes (slow)

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To correct this at rate of

\frac{1}{6}

minutes per hour:

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Time needed =

2 \div \frac{1}{6} = 12

hours

Therefore, watch will show correct time 12 hours after 10 AM Wednesday

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This is 10 PM Wednesday