Answer:
$8190
Explanation:
So we know that were putting away $2 each month from our allowance.
Jan-$2
Feb-$4
March-$8
April-$16
Ok so we already put away 4 months of our allowance from 12. So we need 8 more months to count how much.
So lets add: 2 + 4 + 8 + 16=30
Now we need to figure out how much in May and so on.
May- 16x2=32
June-32x2=64
July-64x2=128
August-128 x 2=256
September-256 x 2=512
October-512 x 2=1024
November-1024 x 2=2048
December-2048 x 2=4096
In total to add:
2 + 4 + 8 + 16 + 32 +64 + 128 + 256 + 512 + 1024 + 2048 + 4096 = 8190
Hope this helps :)