Me with this question and include the explanation and working so i can understand : )

A. The area of SHN=base*h/2= SN*HT/2=21*10/2=21*5=105 cm^2
b. Shaded area=A SMN+A SNQ - A SHN= SN*QR/2+SN*QR/2- 105 cm^2
                        =21*24/2+21*24/2-105 cm^2=
                         =504-105 cm^2=399 cm^2

The question is kind of confusing. if it's asking how many variations of answers can you give. then do 4^5 for your answer.this would be something like the first question could be a and the 2nd c or first b next c etc. if you can, ask the teacher for a better confirmation of what it's asking. if i'm assuming correctly what it's asking, it's 625 different variations.