Question 607974
No the answer is 64.5 minutes.
Explanation in words:

First understand that the problem presented means that it takes 6*43=258 minutes 
of man-work to paint 4 walls 

Which means that it takes 258/4=64.5 minutes of man-work to paint each wall.

Therefore, it takes 64.5*7=451.5 of man-work to paint 7 walls. 

Finally we derive the answer to the problem as so: it takes 451.5/7=64.5 minutes for 7 people to paint 7 walls.