Proportion exercises

Proportion exercises

direct and inverse proportion

P70. The wages of 3 men for 4 weeks is $108. At the same rate of pay, how many weeks will 5 men work for $135?

•  $\frac{mens\cdot weeks}{wages}=\frac{3\cdot4}{108}=\frac{5\cdot x}{135}$  

• x=3

P81 It is now between 10:00 and 11:00. Six minutes from now, the minute hand of a watch will be exactly opposite the place where the hour hand was three minutes ago. What is the exact time now?

•  $\frac{Minutes}{Hours}=\frac{60}{5}=\frac{12}{1}$  

• After 6 minutes, minute hand at x+6. hour hand at 3 minutes ago, it is at 50+5(x-3)/60.

• Opposite place (half way = 30 minutes) 

• 50+5(x-3)/60=x+6+30, x=15