Question 1014099
 Waseem score 30% of the marks in an exam,and fails by 60 marks. \
Waqar scores 40% of the marks in the same exam and passes by 20 marks .\
What is the maximum number of marks in this exam?
:
let m = maximum marks on the exam
let p = no. of marks required to pass
:
" Waseem score 30% of the marks in an exam,and fails by 60 marks."
.3m = p - 60 
" Waqar scores 40% of the marks in the same exam and passes by 20 marks "
.4m = p + 20
:
Use elimination here
Subtract the 1st equation from the 2nd equation
.4m = p + 20
.3m = p - 60
-------------subtraction eliminates p, find m
.1m = 80
m = 80/.1
m = 800 is the maximum number of marks
:
:
:
See if that checks out, find p
.4(800) = p + 20
320 - 20 = p
p = 300 is passing
See if that works in the 1st equation; .3m = p - 60
.3(800) = 300 - 60
240 = 240, confirms our solution