Question

The temperature at 12 noon was 45ºC above zero. If it decreases at the rate of 5ºC per hour, when would it reach 10ºC below zero? *​

Answer 1

Step-by-step explanation:

$given \\ a t\: 12 \: noon \: temperature \: is \: 45 \: degree \: celcius \\ rate \: of \: decreasing \: temperature \: = 5 \: degree \: celcius \: per \: hour \\ at \: 1 \: pm \: \: it \: will \: be \: 40 \: \\ at \: 2pm \: it \: will \: be \: 35 \\ at \: 3pm \: it \: will \: be \: 30 \\ at \: 4 \: pm \: it \: will \: 25 \\ at \: 5 \: pm \: it \: will \: be \: 20 \\ at \: 6 \: pm \: it \: will \: be \: 15 \\ at \: 7pm \: it \: will \: be10 \\ at \: 8pm \: it \: will \: be \: 5 \\ at \: 9pm \: it \: will \: be \: 0 \\ at \: 10pm \: it \: will \: be \: - 5 \\ and \: finally \: at \: 11pm \: it \: will \: be \: - 10 \: degre e\: celcius \\ so \: required \: time \: = 11pm$