q1: 45% bc u have to divide the amount of pens w the total amount of students which is 90/200 and that’s 0.45, also 45%
q2: 9.5% bc now u have to divide the amount of pens only left handed students use, so when u find how many pens left handed students use, that’s 19, and again, u must divide it w 200 so 19/200 equals to 0.095 which is also 9.5%
q3: no
q4: not sure but i think the answer is no