Let's first break it down to the time 8 people need for one wall. That would be 10 minutes, right? If one person would have to do it in stead of 8, you'd expect him to take 80 minutes.
To paint 7 walls, he would nee 7x80 = 560 minutes. 10 people would do that 10 times faster, ie., 56 minutes.
I know puzzles like these always have a mindtrick. Did I miss anything?? ;-)
7 ×5 = 35 and 5 × 7 = 35
ans is 35
< P is a right angle.....a right angle is 90 degrees.
< P and < Q form a linear pair....a linear pair, when added, = 180 degrees
so if < P is 90.....and when added to < Q = 180...
90 + Q = 180
Q = 180 - 90
Q = 90 <== so < Q is also a right angle...measures 90 degrees
