Problem Solving

7.4 Problem Solving


Kamil bought two rope cords. One rope cord is blue and has a length of 1 metre. The other rope cord is red and has a length of 3 metres. State the ratio for the red rope to the blue rope.

Solution :

Length of red rope : Length of blue rope

= 3 m : 1 m

Ratio for the length of red rope to blue rope 3:1.



A printing machine can print 240 posters in 1 hour and 20 minutes. How long, in minutes, is required to print 900 of the same posters?


\(\frac{240\text{ posters}}{1\text{ hour }20\text{ minutes }}\to\frac{240\text{ posters}}{80\text{ minutes }}\to\frac{3\text{ posters}}{1\text{ minute}}=3\text{ posters per minute}\)

To print 900 posters,

\(900\text{ posters}\div \frac{3\text{ posters}}{1\text{ minute}} =300\text{ minutes}\)