Question

A watch which loses time uniformly is
5 minutes fast at 7 am Monday and
becomes 7 minutes slow at 7 pm
Friday. When was this watch 2
minutes slow?​

Answer 1

$\large\bold{\underline{\underline{{Question:-}}}}$

• A watch which loses time uniformly is 5 minutes fast at 7 am Monday and becomes 7 minutes slow at 7 pm Friday. When was this watch 2 minutes slow?

$\large\bold{\underline{\underline{{Given:-}}}}$

• A watch which loses time uniformly is 5 minutes fast at 7 am Monday and becomes 7 minutes slow at 7 pm Friday.

$\large\bold{\underline{\underline{{To\:Find:-}}}}$

• When was this watch 2 mins slow.

$\large\bold{\underline{\underline{{Solution:-:-}}}}$

$\red{★}$Time from 8 am on Sunday 8 pm on following Sunday :-

$\orange{↬}$7 days 12 hours = 180 hours.

$\green{↬}$The watch gains (5+5 4/5) min or 54/5 min in 180 hours.

Now,

$\blue{↬}$54/5 min are gained in 180 hours.

$\purple{↬}$5 min are gained in (180 × 5/54 × 5) hours.

$\pink{↬}$83 hours 20 min.

${↬}$3 days 11 hours 20 min.

$\red{★}$After 8 a.m. of Sunday It will be correct at 20 min past 7 p.m. on Wednesday.

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