West Bengal Board Solutions for Chapter: Measurement of Time, Exercise 2: Let's do ourselves-19.1

Today I have history examination. Exam started at $11:30 \mathrm{a}.\mathrm{m}.$ Teacher's digital wrist watch is showing $13:15$. Find how long I had already written the examination. If the exam is to end at $2:30 \mathrm{p}.\mathrm{m}.$, how long shall I be able to write the examination. When the exam will be over, let me find from before what will the digital watch of the teacher read.

To reach Father's office from home, it takes $2 \mathrm{hrs}$ $27 \min$ but while returning to home, it takes $2 \mathrm{hrs}$ $51 \min$. Calculate how long it takes in total to go Father's office and back. (If the time is $x \mathrm{hours}$and $\mathrm{y} \min$, find $x+y?$)

$$\begin{gathered} \mathrm{hr} \min \sec \\ 8 32 41 \\ + 18 42 23 \\ \mathrm{\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_} \\ 74 64 \\ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \\ =\mathrm{\_\_\_\_\_} \mathrm{hr} \mathrm{\_\_\_\_\_} \min \mathrm{\_\_\_\_\_sec} \end{gathered}$$

$$\begin{gathered} \mathrm{hr} \min \sec \\ \overline{)8} \overline{)60+11} \\ \cancel{9} \cancel{12 } \overline{)60+37} \\ \left(-\right) 3 38 41 \\ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \end{gathered}$$

Do the addition: $\left(4 \mathrm{hr} 33 \min 20 \sec \right)+\left(9 \mathrm{hr} 52 \min 25 \sec \right)$. (If the time is $x \mathrm{hours}, \mathrm{y} \min$ and $z \sec$, find $x+y+z$)

Do the subtraction: $\left(6 \mathrm{hr} 42 \min 2 \sec \right)-\left(2 \mathrm{hr} 55 \min 42 \sec \right)$

Find the addition: $\left(18 \mathrm{hr} 19 \min 15 \sec \right)+\left(9 \mathrm{hr} 55 \min 48 \sec \right)$(If the result is $x \mathrm{hours}, \mathrm{y} \min$ and $z \sec$, find $x+y+z$)

Find the subtraction: $\left(23 \mathrm{hr} 7 \min \right)-\left(19 \mathrm{hr} 29 \min 18 \sec \right)$(If the time is $x \mathrm{hours}, \mathrm{y} \min$ and $z \sec$, find $x+y+z$)