Hot water kept in a beaker placed in a room cools from $70^{\circ}C$ to $60^{\circ}C$ in $4$ minutes. The time taken by it to cool from $69^{\circ}C$ to $59^{\circ}C$ will be

$A$ body cools down from $75^{\circ}C$ to $60^{\circ}C$ in $10 \text{ minutes}$. It will cool down from $65^{\circ}C$ to $55^{\circ}C$ in a time:

$A$ liquid cools from $50^oC$ to $45^oC$ in $5$ minutes and from $45^oC$ to $41.5^oC$ in the next $5$ minutes. The temperature of the surrounding is ...... $^oC$.

Two friends $A$ and $B$ are waiting for another friend for tea. $A$ took the tea in a cup and mixed the cold milk and then waits. $B$ took the tea in the cup and then mixed the cold milk when the friend comes. Then the tea will be hotter in the cup of

One day in the morning,Ramesh filled up $\frac{1}{3}$ of a bucket with hot water from a geyser to take a bath. The remaining $\frac{2}{3}$ was to be filled with cold water (at room temperature) to bring the mixture to a comfortable temperature. Suddenly,Ramesh had to attend to some work that would take $5-10 \text{ min}$ before he could take a bath. He had two options: $(1)$ fill the remaining bucket completely with cold water and then attend to the work,$(2)$ first attend to the work and then fill the remaining bucket just before taking a bath. Which option do you think would have kept the water warmer? Explain.

$A$ body cools from a temperature $3T$ to $2T$ in $10$ minutes. The room temperature is $T$. Assume that Newton's law of cooling is applicable. The temperature of the body at the end of the next $10$ minutes will be