Question

The temperature of the furnace is 1200 and cool at a rate of 15 per minute the temperature of another furnace is 900 and is heat at a rate of 5 per minutes after how many minutes will the furnace be at the same temperature

Answer 1

After 15 minutes, the temperature of both the furnaces will be same.

Explanation:

Let
`x` be the minutes when the temperature of both becomes same.

Now, as per question:

Temperature of the furnace after
`x` minutes that is cooling at the rate of 15 degree per minute is given as:

`T=1200-15x`

Temperature of the furnace after
`x` minutes that is heating at the rate of 5 degree per minute is given as:

`T=900+5x`

Now, equating both the temperatures, we get

`1200-15x=900+5x\\1200-900=15x+5x\\300=20x\\x=(300)/(20)=15\ min`

Therefore, after 15 minutes, the temperature of both the furnaces will be same.