This question already has an answer here:
What is correct here?
it could pay your mortgage and car payments
it could pay your mortgage and car payment
The monthly payments are separate and distinct so #1 sounds right, but in #2, mortgage and car modify payment, a single payment—a single mortgage payment, and a single car payment. Instead of saying 'your mortgage payment and car payment' the sentence just leaves out one 'payment'.
If 'or' was used, then payment, singular, would be correct:
- it could pay your mortgage or car payment