Tina had twice the number of rubber bricks as David. Tina used all her bricks to build 9 identical ships. David used all his bricks to build 6 identical ships. Tina used 9 more bricks than David for each ship. How many bricks did David have?
| |
Tina |
David |
| Number |
9 |
6 |
| Value |
1 u + 9 |
1 u |
| Total value |
9 u + 81 |
6 u |
Number of rubber bricks that David used for each ship = 1 u
Number of rubber bricks that Tina used for each ship = 1 u + 9
Number of rubber bricks that David had
= 6 x 1 u
= 6 u
Number of rubber bricks that Tina had
= 9 x (1 u + 9)
= 9 u + 81
Tina had twice the number of rubber bricks as David.
2 x 6 u = 9 u + 81
12 u = 9 u + 81
12 u - 9 u = 81
3 u = 81
1 u = 81 ÷ 3 = 27
Number of bricks that David had
= 6 u
= 6 x 27
= 162
Answer(s): 162
