The LCM is: <span>2,7,7,2,0.</span>
The ratio 5/6 is equivalent to 275/330
5:6 ⇔ 275:330
Quick answer: 68oF <<<<
A quick way to figure this out is to double the C temperature and add 30, just so you get an estimate.
F ~ 2*20 + 30 ~ 70oF
Now let's use the actual formula
F = 9/5 * C + 32
F = 9/5 * 20 + 32
F = 180/5 + 32
F = 36 + 32
F = 68o
68oC <<<<< answer.