Let number of biscuits baked = x. (3/7)x are in container a. The remainder = (4/7)x, because (3/7)x + (4/7)x = (7/7)x = x. Now, (5/8)*(4/7)x = (5/14)x are in container b. The rest = (3/8)*(4/7)x, because (5/8)*(4/7)x + (3/8)*(4/7)x = (8/8)*(4/7)x = (4/7)x. So, (3/8)*(4/7)x = (3/14)x are in container c.
