Question -
Answer -
Temperature at 12 noon was 10┬░C above zero i.e. +10┬░C
Rate of decrease in temperature per hour = 2┬░C
Number of hours from 12 noon to midnight = 12
тИ┤ Change in temperature in 12 hours
= 12 ├Ч (-2┬░C) = -24┬░C
тИ┤ Temperature at midnight
= +10┬░C + (-24┬░C) = -14┬░C
Hence, the required temperature at midnight =-14┬░C
Difference in temperature between + 10┬░C and -8┬░C
= +10┬░C тАУ (-8┬░C) = +10┬░C + 8┬░C = 18┬░C
Number of hours required = 18тИШC/2тИШC= 9 hours
тИ┤ Time after 9 hours from 12 noon = 9 pm.