Statement 1 only guarantees we have at least 14 of the P flowers, and Statement 2 only guarantees we have an even number of the G flowers (since we must be able to multiply that number by 1.5 = 3/2 and get a whole number answer). But there remain many possible numbers of P flowers using either Statement alone.

Using both Statements, we have 14 white P flowers. So we have 40 flowers left, which are either yellow P flowers or G flowers. If we have 50% more of the G flowers, or 3/2 times as many G flowers, then yellow P flowers and G flowers are in a 2 to 3 ratio. So 2/5 of the 40 flowers are yellow P flowers, or 16 of them, so we have 14 +16 = 30 of the P flowers in total, and the answer is C.