Ritin has 21/5 litres of lemonade of which he distributed 13/4 litre lemonade . how much lemonade left with him

Ritin has 21/5 lemonade and he distributed meaning he took away 13/4 liters of lemonade. Find a common denominator  between 5 and 4. Since we know 5 times 4 is 20 the smallest common denominator so lets multiply 21/5 by 4 getting 84/20 and multiply 13/4 by 5 getting 65/20. Since both fractions have 20 as the denominator, subtract 84/20 by 65/20 and you get 19/20 liters of lemonade as your answer.

Answer is 19/20 liters of lemonade Ritin has left

Were is the diagram?

Ithink it is15not sure tho