So it takes 7×5=35 minutes for Lily to make five flowers.
Ping Li made five flowers in 30 minutes.
So Lily spent a long time making a flower.
It takes Lily 35-30 minutes longer to make five flowers than Li Ping.
Then lily 1 min makes 1 flower more than Li Pinghua 1 flower.
So it takes a long time for lily to make a flower, 1 minute.