Hi Sazza! That neon green font is kinda tough to read...

See Jhevon's brilliant explanation.

2) If a Steel Bar 90 cm long weighs 3.6 kg, find the weight of a similar length of 1.5 m.

Have you heard of proportions? A comparison of two ratios?

We've got to have like units. One 1 m = 100 cm. So the 1.5 m = 150 cm.

Just solve for x:...

3) A Long haul truckie knows that his truck uses 153 litres of fuel for a trip of 850 km. How much fuel must he carry for a trip of 1350 km?

Make a proportion.

You should get:..