9514 1404 393
Answer:
350
Explanation:
There are 4 ratio units of A blocks and 3 ratio units of C blocks, so 1 more ratio unit of A blocks than of C blocks. That 1 ratio unit corresponds to 50 blocks, since there are 50 more A blocks than C blocks.
There are 7 ratio units of B blocks, so the number of B blocks is ...
7×(50 blocks) = 350 blocks . . . . . number of B blocks