"propose an answer" is correct and usable in written English.
You can use it when you are asking someone to provide a solution to a problem. For example: "I am having difficulty coming up with a solution for this problem. Can you propose an answer?".
We propose an answer to that question in our new research paper.
In a paper published in the 5 October Nature, Hartmann and her graduate student Joseph Solomon propose an answer in the form of a mathematical model.
In this month's Animal Behaviour, a team of biologists propose an answer: Birds with a greater repertoire of song "syllables" are less likely to carry parasites.
The oldest lore we have are attempts to propose an answer to these questions for the species, epics that place humankind in a cosmos that is not alien to them, however marginal or precarious their place in it.
Before we propose an answer to this question, we return to the search based on fused elements, which was tested in Experiment 2. Search for orthogonal targets among single-orientation distractors (mimicking search based on fused elements) was not faster than search for single-orientation targets among orthogonal distractors.
Then he proposed an answer to his own question.
Karlheinz Brandenburg, director of the Fraunhofer Institute for Digital Media Technology in Ilmenau, Germany, proposes an answer.
Later in the arguments, Justice Alito proposed an answer to that question.
In a recent article in Ballet Review, Jeffrey Edwards, a former New York City Ballet dancer, proposed an answer.
It proposed an answer based on the concept of a "good life" rather than a "better life".
But asking "why precisely now?" is less daft, and a provocative new study proposes an answer: soaring food prices.
