50*500*5%= 1250 yuan

The remaining tax is: 3080- 1250= 1830 yuan.

For the part exceeding 500 yuan to 2000 yuan = 70 yuan, the maximum payment per person is 700 * 10%.

At least1830/70 = 26.142857 = 27 people exceed 500 yuan to 2000 yuan.

Therefore, there may be at most 50-27=23 employees whose monthly salary does not exceed 1300.