Express 68 degree F in degree C.Multiple Choice: A) 7.0 degree C B) 20 degree C C) 36 degree C D) 181 degree C

jayjay,

when converting from Celsiusto Fahrenheit, the best way to do it is to realize that they have similar log scales and can be determined by knowing only one step, actually.

To go from F to C                 to go from C to F

1) add 40                            1) add 40

2) multiply by 5/9                  2) multiply by 9/5

3) subtract 40                       3) subtract 40

You see from this that there is no need to remember any equation other than multiplying by either 5/9 or 9/5 since step 1 and step 3 are identical. How do you know which one to use?  Just notice if you go from large scale to small scale use 5/9 and if you go from a large scale to a small scale then use 9/5.

Therefore the answer to your question is:

1) 68 +40= 108

2) 108 * (5/9)= 60

3) 60-40=20 C