Jane makes toy bears. When she works with an assistant she makes 80% more bears per week, and works 10 percent fewer hours each week. Having an assistant increases Jane's output of toy bears per hour by what percent?
Lets x=total toyes per week
t= hours in week
y=jane's output per hour
Befor assistant - he makes toyes x=t*y => y=t/x
After assistand he makes toyes 1.8x=0.9t*y =>y =2t/x
So 100 % ... C is the answer