type 4 time gained or lost by clock Detailed Explanation And More Example

Answer: (a)

Required result = $(720/11 - x) (60×24 /x) min$

Here, x = 88

Therefore, required result =$ (720/11 - 88) (60×24 /88) min$

= $-248/11 × 180/11 min = -368 112/121 min$ (loss as sign in negative)

Answer: (d)

Time from 7 a.m. to 4.15 p.m. = 9 hrs 15 min = $37/4$ hrs 3 min 5 sec of this clock = 3 min. of the correct clock.

= $37/720$ hrs of this clock = $1/20$ hrs of the correct clock

= $37/4$ hrs of this clock

= $(1/20 × 720/37 × 37/4)$ hrs of the correct clock

= 9 hrs of the correct clock

Therefore, The correct time is 9 hrs after 7 a.m., i.e. 4 p.m.

Answer: (a)

Since the time read by the lady was 57 minutes earlier than the correct time,

so the minute hand is (60 - 57) = 3 minute spaces behind the hour hand.

Now, at 5 O' clock, the minute hand is 25 minute spaces behind the hour hand.

To be 3 minute spaces behind, it must gain (25 - 3) = 22 minute spaces.

55 min spaces are gained in 60 min.

22 min spaces are gained in $(60/55 × 22) = 24 min$

Hence, the correct time was 24 minutes past 5.

Answer: (d)

Time from 12 p.m. on Monday to 2 p.m.

on the following Monday = 7 days 2 hours = 170 hours.

Therefore, the watch gains $(2 + 4 4/5) min. or 34/5 min.$ in 170 hrs.

now, 34/5 min. are gained in 170 hrs.

2 min. are gained in $(170 × 5/34 × 2) hrs = 50 hrs.$

Therefore, Watch is correct 2 days 2 hrs. after 12 p.m. on Monday

i.e. it will be correct at 2 p.m. on Wednesday