It is C)


Stmt 1)

Let x be the customer who purchased 1 book
y - 2 books
z- 3 books

To find x

x+y+z=100


x(1)+y(2)+z(3) / 100 = 2

x+2y+3z = 200

INSUFF 2 eqns 3 vars

Stmt 2: y=20

x+y+z = 100
x+20+z=100
x+z=80

1 eqn 2 variables

INSUFF

Combine 1) and 2)

x+2y+3z = 200
x+2(20)+3z = 200
x+3z=160

AND
x+z=80

x=40 y=20 z=40

40*1+20*2 +40*3 = 200 books 100 customers

vishubn wrote:A total of 100 customers purchased books at a certain bookstore last week. If these
customers purchased a total of 200 books, how many of the customers purchased only 1
book each?
(1) None of the customers purchased more than 3 books.
(2) 20 of the customers purchased only 2 books each.


OA C

Lets start with the easy statement. (1) does not give any information about customers who purchased 1 book ? A and D are GONE!

(2) only tells us 20x2=40 books are purchased and we still need to find out what happened to the 160 books and 80 customers ?

B is gone!

so if we can solve this problem it is C otherwise we will pick E

well (1) says None of the customers purchased more than 3 books..AHA!! so it means people either purchased 1, 2 or 3 books. We know how many purchased 2 books so:

Remaning 80 customers either purchased 1 or 3 books and we have to find how many purchased 1 book ? Lets call it X

X (1 book) + ( 80-X) (3 books ) = 160

you dont need to solve it after this point.

You have one equation and one variable!

Choose C! dont waste your time. 8)