Let's set it up first.
1/b + 3/d =
d/db + 3b/db =
(d + 3b)/db
Now we'll take our statements:
S1: We could have b = d = 6, or b = 12, d = 6, so we'll get different results; NOT SUFFICIENT.
S2: We could have b = d = 12, or b = 1, d = 12, so again we'll get different results; NOT SUFFICIENT.
Together, let's use a great formula:
LCM of x,y * GCF of x,y = x * y
So we have
12 * 6 = b * d, or db = 72
This gives us our denominator, so we have
(d + 3b)/db = (d + 3b)/72
But we still don't know d and b! We could have d = 12, b = 6, or d = 6, b = 12. So our answer could be 30/72 or 42/72; NOT SUFFICIENT.
