Answer:
Mary have 90 flowers
Explanation:
Given that Mary had flowers, of which 3/5 were roses and the rest were orchids.
Let Mary had x flowers.
∴ Roses are=

and orchids are

Now, She sold 1/2 of the roses and 1/4 of the orchids. She then had 54 roses and orchids left.
Hence, total flowers i.e roses and orchids sold are

The flowers which left are

⇒
⇒

Therefore, Mary have 90 flowers