I'm a female, weigh 268 lbs. if i work out everyday for 10 months and eat 1800 c. a day could i reach 150 lbs?

Losing Weight: Yes. It is possible. But, setting such a goal may be a fast road to failure...It is too big to get one's mind around sometimes. Setting interim goals of 20 pounds at a time may be a wiser approach.

Can be done: It can be done, loosing 11 lbs a month is a reasonable target. I believe the firs half of your journey will be easier than the second half.