Omar spent 600 dollars for earning 1800 reward points.
Explanation
Omar earns 300 reward points for every 100 dollars he spends.
Suppose, he spent [tex]x[/tex] dollar for 1800 reward points.
Now according to the ratio of "amount of money spent" and "reward points" , the equation will be......
[tex]\frac{x}{1800}=\frac{100}{300}\\ \\ 300x=180000\\ \\ x=\frac{180000}{300}=600[/tex]
Thus, Omar spent 600 dollars for earning 1800 reward points.
