HELP PLEASE WILL GIVE BRAINLIST IF CORRECT

a.) First check on the height of the bar that ranges between 20 and 24 which is 6. The 6 is the number of students who bought 20 books or more, so get the percentage of those students who bought 20 or more books; divide 6 which is the number of students who bought 20 books or more with the total number of students which is 40 then multiply with 100.

% of students who bought 20 or more books = 6/40 ×100

=15

Step-by-step explanation:

b.) Find the area of a trapezium

= 1/2 × {a+b} × h

= 1/2 × {9 + 13} ×12

= 132

= 1/2 × {13 + 6} × 12

= 108

Mean no. of books bought = 132 + 108

= 240

is there a picture

step-by-step explanation:

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.