Fill in the blanks.
• 4 groups of 9 is __P__ less than 2 groups of 19.
• 3 groups of 5 is __Q__ more than 6 groups of 2.
• 7 groups of 6 is __R__ less than 9 groups of 6.
• 8 groups of 8 is __S__ more than 4 groups of 15.
| P | Q | R | S | |
| A | 3 | 3 | 10 | 4 |
| B | 2 | 4 | 12 | 6 |
| C | 2 | 3 | 12 | 4 |
| D | 3 | 4 | 10 | 6 |