Potatohead Corporation had 150,000 ordinary shares outstanding on January 1, 2018. On April 1, 2018, Potatohead issued an additional 80,000 shares. On July 1, 2018, Potatohead repurchased 60,000 ordinary shares and cancelled them. On October 1, 2018, Potatohead issued an additional 20,000 ordinary shares.

Required: 

a. What was the weighted average number of ordinary shares outstanding in 2018? 

b. Assume that on July 1, 2018, Potatohead repurchased the shares and held them as treasury shares. Will the weighted average number of ordinary shares outstanding in 2018 change from the amount in part (a)? Why or why not?