Some balls are in a bag. 21 balls made by rubber, 17 balls are heavy and 16 balls colour is black. 3 rubber balls are black in colour but are not heavy. 8 balls are heavy and black in colour but are not made by rubber. 2 rubber balls are heavy and the colour is black. 6 balls are heavy neither made by rubber nor colour is black. How many total balls are in the bag?
1
38
2
50
3
45
4
30