50 Jars sit on a shelf, of which 12 are red and not round; and 30 are round and not red. How many jars sit on the shelf

[Gmat_mission]

50 Jars sit on a shelf, of which 12 are red and not round; and 30 are round and not red. How many jars sit on the shelf that is both red and round?

1. There are only 5 jars on the shelf which are not red and not round.

2. Of the round jars, The number of nonred is 10 times the number of red jars.

Answer: D

Source: Economist