A complete load of concrete = 8 parts gravel + 7 parts water + 5 parts cement.
Total number of parts in every load = 8 + 7 + 5 = 20 parts
If total load = 220 kg, then 20 parts = 220 kg
Divide each side by 20 : 1 part = 11 kg
gravel = 8 parts = 8 x 11 kg = <em>88 kg</em>
water = 7 parts = 7 x 11 kg = <em>77 kg</em>
cement = 5 parts = 5 x 11 kg = <em>55 kg</em>
<u>Check:</u> 88 + 77 + 55 = 220 yay !
For every person that walked there were 12 who drove and if the 270 made the trip then 87 walked
A row goes across like this.
@ @ @ @ @ @ @ @ @
All you have to do is multiply: -3.25•-1.56=5.07. A negative times a negative is a positive :)
