Solution:

Tulips

Explanation:
There are two Lips are under your nose.
2 Lips = tulips.

Solution:

25

Explanation:
== Equation1 ==
RedFlower + RedFlower + RedFlower = 60
=> RedFlower = 20

== Equation2==
RedFlower + 5BluePetals + 5BluePetals = 30
=> 20 + 10BluePetals = 30
=> 10BluePetals = 10
=> 1BluePetals = 1

== Equation3 ==
5bluePetals + 2yellowFlower = 3
=> 5 + 2yellowFlower = 3
=> 2yellowFlower = 2
=> 1yellowFlower = 1

== Required ==
YellowFlower + RedFlower + 4BluePetals = ?
=> 1 + 20 + 4 = 25 ... The Answer

Solution:

TuLip(2 lip)

Solution:

False.

Some flowers are used to make perfumes but lily are not the only type of flowers and so it is not necessarily true that lily makes perfumes.

Solution:

Rose bought lilies, Lily bought jasmines and Jasmine - roses. By the condition, the girl, who bought the roses isn't Rose. She's not Lily either, because Lily answered to that girl. So, the roses were bought by Jasmine, and thus lilies were bought by Rose and jasmines by Lily.

Solution:

There are three roses and four bees.