Answer: 40
Step-by-step explanation: First, 1/5 of the 80 houses were sold last month. 80x1/5 is 16. We now know that 16 of the houses were sold, so 80-16 is 64. In the second part of the question, 5/8 of the remaining houses were sold this month. So, 64x5/8 equals 64 divided by 8 times 5. 8x5=40, and we have 40 houses left over. Therefore, there are 40 houses left to be sold.