MAT Exam 2020 Paper

Concept:When a clock gains 10 minutes in 24 hours, in 24 actual hours it shows $24$ h $10$ min. Use this ratio to convert the faulty clock reading into actual time.Explanation:From 8 am to 8 am the next day, actual time elapsed is $24$ hours.In this period, the faulty clock shows $24$ h $10$ min.So, $24$ h $10$ min $=24+\frac{10}{60}=\frac{145}{6}$ hours shown by the clock.Therefore, $\frac{145}{6}$ faulty hours $=24$ actual hours.The clock indicates 1 pm on the following day, so the faulty time elapsed from 8 am is $24+5=29$ hours.Actual time elapsed in these 29 faulty hours is:$29 \times \frac{24}{(145/6)} = 29 \times \frac{144}{145} = 28.8$ h $=28$ h $48$ min.Adding this to the initial correct time 8 am:$8$ am $+ 28$ h $48$ min $=12:48$ pm on the following day.Answer:The right time when the clock indicates 1 pm on the following day is 12:48 pm, i.e. Option B.