E) 1/5
Method 1
Use your calculator to find the decimal version of each fraction
4/10 = 0.4012/25 = 0.4814/20 = 0.7028/50 = 0.561/5 = 0.20
We see that 0.20 is the smallest decimal of the list, so 1/5 is the smallest fraction of the list.
Method 2
To compare fractions, we need to get all of the denominators to the same value. A good target is the lowest common denominator (LCD)
In this case, the LCD is 100
4/10 = 40/100 multiply top and bottom by 1012/25 = 48/100 multiply top and bottom by 414/20 = 70/100 multiply top and bottom by 528/50 = 56/100 Β multiply top and bottom by 21/5 = 20/100 Β multiply top and bottom by 20
The last fraction has the smallest denominator, so 1/5 is the smallest.