9514 1404 393
Answer:
 96
Step-by-step explanation:
In terms of blocks, the box dimensions are ...
 (14 in)/(3.5 in/block) = 4 blocks
 (21 in)/(3.5 in/block) = 6 blocks
Then the volume in terms of blocks is ...
 V = LWH
 V = (4)(4)(6) = 96 . . . . blocks
There are 96 blocks in the set.