Respuesta :
Solution: We are given that:
5 people can paint 7 walls in 21 minutes
Therefore, 1 person can paint 7 walls in [tex] 21 \times 5=105 [/tex] minutes
Which means 1 person can paint 1 wall in [tex] \frac{105}{7} =15 [/tex] minutes
Now, 3 people can paint 1 wall in [tex] \frac{15}{3} =5 [/tex] minutes
Therefore, 3 people can paint 5 walls in [tex] 5 \times 5=25 [/tex] minutes
