You will want to subtract the amount he ran on Monday from the amount on Tuesday. In order to subtract fractions, we must set them to the same denominator (bottom number). In order to do this, we must multiply 3/5 by 6/6 (the denominator on tuesday) which gets us 18/30. Then, for Tuesday, we must multiply 2/6 by 5/5 (the denominator on Monday) which is 10/30. Now, we can do Monday-Tuesday, 18/30-10/30 which gets us 8/30, if we simplify this, we get 4/15 :)
