Afraction changes from 3/4 to 4/10. the numerator changed by %; the denominator changed by %; the value of the fraction changed by approximately %.

The change from 3/4 to 4/10 is found by obtaining and applying the LCD:

15/20 to 8/20 is a negative change, and the amount of the change was -7/20.

We compare this result to the original value, 15/20, to obtain the percentage change in the fraction:

   -7/20
= -7/15 = -0.467  =>  -46.7%
   15/20