Official Solution:On a certain farm, the ratio of pigs to ostriches is 7 to 5. Are there more than 14 lamas on the farm? \(\frac{pigs }{ostriches }=\frac{7}{5}\)
(1) The ratio of ostriches to lamas is 4 to 3.
\(\frac{ostriches }{lamas }=\frac{4}{3}=\frac{20}{15}\)
\(\frac{pigs }{ostriches }=\frac{7}{5}=\frac{28}{20}\)
So, \(pigs:ostriches:lamas=28:20:15\). The minimum number of lamas is therefore 15. Sufficient.
(2) There are five more ostriches than lamas, and there are 8 more pigs than ostriches.
There are 8 more pigs than ostriches: \(7x - 5x=8\). This gives \(x=4\). So, the number of ostriches is \(5x=20\), and therefore the number of lamas is \(20-5=15\). Sufficient.
Answer: D