Answer:
9 Blue Cupcakes
Explanation:
First, draw a diagram.
(suppose the blank stars are the pink cupcakes, black stars are the purple cupcakes and the half blank-half black stars are the blue cupcakes)
oooo
oooo
oooo
oooo
oooo
oooo
Then, figure out how much is 1/4 of 24, which is 6.
✩✩✩✩
✩✩oo
oooo
oooo
oooo
There are 18 cupcakes left. Then, figure out what 1/2 of 18 is, which is 9.
✩✩✩✩
✩✩★★
★★★★
★★★o
oooo
oooo
Finally, see how many are remaining, which are 9 cupcakes left.
✩✩✩✩
✩✩★★
★★★★
★★★✯
✯✯✯✯
✯✯✯✯
Hopefully this helped!
-✩sandwichchan✩