Question

A watch is $1$ minute slow at $1:00$ P.M. on Tuesday and $2$ minutes fast at $1:00$ P.M. on Thursday. Assuming the hands of the watch move with uniform speeds in that duration, when did it show the correct time?

• A. $1:00$ A.M. on Wednesday
• B. $5:00$ A.M. on Wednesday
• C. $1:00$ P.M. on Wednesday
• D. $5:00$ P.M. on Wednesday

Answer 1

The correct option is B $5:00$ A.M. on Wednesday

Time from $1:00$ P.M. on Tuesday to $1:00$ P.M. on Thursday $=48$ hours.
So, the watch gains $(1+2)=3$ minutes in $48$ hours.
Now, $3$ minutes are gained in $48$ hours.
So, $1$ minute is gained in $\frac{48}{3}=16$ hours.
Thus, the watch showed the correct time $16$ hours after $1:00$ P.M. on Tuesday, i.e., $5:00$ A.M. on Wednesday.