To find out how much further Saji needs to swim, we need to subtract the distance he has already swum from the total distance he swims every day.
First, let's calculate the total distance Saji swims every day. We are told that he swims 1/3 mile every day. So, the total distance he swims is 1/3 mile.
Next, we need to subtract the distance he has already swum, which is 1/5 mile, from the total distance. To do this, we can subtract 1/5 mile from 1/3 mile:
1/3 - 1/5
To subtract fractions, we need to have a common denominator. In this case, the common denominator is 15.
(1/3) * (5/5) - (1/5) * (3/3)
5/15 - 3/15
Now, subtract the numerators:
(5 - 3)/15 = 2/15
So, Saji should swim a further 2/15 mile.