The dance group initially had [[$ 12 $]] dancers. By what percentage did the number of dancers increase or decrease, when the number of dancers

a) first increased by [[$ 100 \% $]] and then decreased by [[$ 25 \% $]]?



The amount of dancers increased decreased by [[$ \% $]]

b) first increased by [[$ 50 \% $]] and then decreased by [[$ 50 \% $]]?



The amount of dancers increased decreased by [[$ \% $]]

c) first increased by [[$ 200 \% $]] and then decreased by [[$ 75 \% $]]?



The amount of dancers increased decreased by [[$ \% $]]