Answer:
What is 3/5 of a whole? 
3 / 5 = 0.6 
 
Explanation:
If you insist on converting 3/5 to a whole number, the best we can do is round the decimal number up or down to the nearest whole number. 3/5 rounded up to the nearest whole number is 1 and 3/5 rounded down to the nearest whole number is 0.