Given
In first week , he read 50 pages.
After first week , he read 65 pages.
Find
Expression represents the total number of pages Saul has read
Explanation
Let w represents the number of weeks since he first started reading.
Assume y represent number of pages.
when w = 1 then y = 50 ; w = 2 then y = 65+50=115
we know the equation of line
y = mw + c
so ,
50 = m + c .........(1)
and
115 = 2m + c ............(2)
on solving equation (1) and (2) , we get m = 65 and c = -15
so ,
y = 65w - 15
Final Answer
Therefore , the correct option is 3rd