# Math

A cup of coffee has cooled from 98degreesC to 50degreesC after 15 minutes in a room at 25degreesC. How long will it take to cool to 40degrees​C?

Someone else helped me on a problem similar to this, however I keep getting it wrong by decimals. i.e the answer is 35.987 but i put in 35.867
I can't imagine why I'm getting it wrong, ive checked and double checked my formulas over and over
Thank you

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1. https://www.jiskha.com/questions/1776107/A-cup-of-coffee-has-cooled-from-95degreesC-to-60degreesC-after-13-minutes-in-a-room

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Writeacher

25+(98-25)e^(-15k) = 50
k = 0.0714

So, to find t when T=40,
25+73e^(-0.0714t) = 40

Is this what you did?
If not, what did you do?

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