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A pan filled with hot food cools form 94^(@)C to 86^(@)C in 2 minutes . When the roo temperature is 20^(@)C. How long will it cool from 74^(@)C to 66^(@)C ? |
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Answer» 2 MINUTES In Case (i), `(94-86)/(2)prop((94+86)/(2)-20)` `IMPLIES (8)/(2)prop(90-20)` or `4prop70""….(1)` In Case (ii), `(74-66)/(t)prop((74+66)/(2)-20)` `(8)/(t)prop(70-20)` `(8)/(t)prop50""....(2)` Dividing (1) and (2) `(t)/(2)=(70)/(50)` `t=(14)/(5)` `t=2.8` minutes |
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