Question 22201
Wednesday = w
Monday = m
Friday = f
w+m+f=820
w=2m-40------>2m-w=40
f=0.5(2m-40)
f=m-20------->m-f=20


w+m+f=820
2m-w=40
3m+f=860 (new equation)


3m+f=860
m-f=20
4m=880
m=220 ////////////  f=220-20=200 ////////////// w=2(220)-40=400

Hence, on Wednesday she read 400 pages on friday she read 200 pages and on monday she read 220 pages.