Answer:No, he doesn't have enough wood for the roof.
Explanation:
Total length of Hank's board is 1.75 meters. He used 0.8 meter to build the walls of a birdhouse. This means that the length of the board left would be
1.75 - 0.8 = 0.95 meters
He used 0.4 of what is left for the floor. This means that the length of the board left would be
0.95 - 0.4 = 0.55 meters
He needs 0.6 meter for the roof. Since he has only 0.55 meters left, then, he doesn't have enough wood for the roof.