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

Answer: (d)

Required result =$ (720/11 - x) (60 × 24 /x)$ min Here, x = 62

Therefore, required result = $(720/11 - 62) (60 × 24 /62)$ min

= $38/11 × 720/31 $min = 80 $80/341$ min gain (gain as sign is positive)

Answer: (b)

Method I

As we know that in a correct clock, the minute hand gains 55 min spaces over the hour hand in 60 min.

To be together again, the minute hand must gain 60 min over the hour hand.

60 min are gained in $(60/55 × 60) min = 65 5/11 min$

But they are together after 63 min.

Therefore, gain in 63 min =$ (65 5/11 - 63) = 2 5/11 min = 27/11 min$

Gain in 24 h = $(27/11 × 60 × 24/63) min = 4320/77 min = 56 8/77 min$

As result is positive, therefore clock gains 56 $8/77$ min.

Method II

In the given question, x = 63 min

According to the formula,

Required result = $(720/11 - x) (60 × 24 /x) min = (720/11 - 63) (60 × 24 /63 ) min$

= $27/11 × 60 × 8 /21 = 56 8/77 $min (gain as sign in positive)

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

Answer: (b)

Required result =$ (720/11 - x) (60 × 24 / X)$ min Here, x = 58

Therefore, required result = $(720/11 - 62) (60 × 24 /58)$ min

= $82/11 × 720/29 min = 185 25/319 min $gain (gain as sign is positive)

Answer: (c)

Therefore, required result = $(720/11 - x) (60 ×24 / 76) min$

Here, x = 76 Therefore, required result = $(720/11 - 76) (60 × 24 /76) min$

= $-116/11 × 360/19 min$

= $- 199 169/206 min$ (loss as sign in negative)