You have to find the LCD (lowest common denominator) to be able to order them.
The LCD is 40.
So then you multiply the fraction to get the LCD
3/4 * 10/10= 30/40
7/8 * 5/5= 35/40
1/5 * 8/8= 8/40
Then determine the order.
8/40 < 30/40 < 35/40
Convert back to original fractions and
Your answer is:
1/5, 3/4, 7/8