3/16 of those who voted liked the plan; 5/8 of those who voted didn't like the plan.
5/8 = 10/16, so together 3/16 + 10/16 or 13/16 of the employees voted, leaving 3/16 who didn't vote.
150 employees didn't vote, so 150 = 3/16 (x) x is total number of employees
At this point, we know that the number who liked the plan is the same number who didn't vote: 150
3/16 (x) * 16 = 150 * 16
3x = 2400
3x / 3 = 2400 / 3
x = 800
3/16 of those 800 like the plan, or 150 employees liked the plan