The phrase "a firm one" is correct and usable in written English.
It can be used to describe something that is solid, strong, or unyielding, often in reference to an opinion, decision, or physical object.
Example: "After much deliberation, she made a firm one regarding her career path."
Alternatives: "a strong one" or "a solid one".
While there is also some evidence that landing on a compliant springboard is less energetically costly than landing on a firm one, it is weaker and the pattern is inconsistent.
At issue is the difficulty in pinning the blame on any one person for risks and decisions taken throughout a firm - one of the main obstacles to building such cases so far.
Maybe it's a hundred and twenty per cent, although that figure isn't a firm one, either.
Someone runs up to a whiteboard and writes a firm ONE in the Hate Calls column.
The floor was not a firm one, because the E.P.A. could issue a waiver if the requirement became "onerous".
"I remember him being a small man with a small hand," Kiefer said, "and his handshake wasn't a firm one.
On the living-room couch, Larson stroked Clooney's leg in a firm, one-way motion, as if brushing clean a billiard table, and then tried to flatten an unruly tuft of his hair.
The firm caused uproar at the end of September by revealing plans that would diddle minority shareholders.In May this year Telecom Italia was bought by Olivetti, a firm one-sixth of its size.
Just as we were starting to unwind, a tall muscular man approached me, gave me a firm one-fingered prod in the shoulder and said: "Hey, I've a bone to pick with you!" How, I wondered, had I managed to get on the wrong side of this giant, and where was the exit door?
He distributed his talents almost equally between the stage and the screen in his later years, and sometimes it appeared that if he had concentrated them both in form and in subject his mark would have been a firmer one.
That's a shame, because we can well imagine wanting a softer ride for freeway travel, and a firmer one for back roads.
