Answer: For every 10 minutes Quincy was inside he spent 3 minutes on Lunch.
Explanation:
Since we have given that
Number of minutes Quincy spent in reading = 20
Number of minutes he spent in eating lunch = 18
Number of minutes he spent in playing cards = 12
Number of minutes he spent in drawing = 10
Total minutes he spent is given by

Ratio of lunch to the total minutes is given by

So, For every 10 minutes Quincy was inside he spent 3 minutes on Lunch.