GMATinsight wrote:
Walkabout wrote:
A store currently charges the same price for each towel that it sells. If the current price of each towel were to be increased by $1, 10 fewer of the towels could be bought for $120, excluding sales tax. What is the current price of each towel?
(A) $ 1
(B) $ 2
(C) $ 3
(D) $ 4
(E) $12
Hello Experts,
EMPOWERgmatRichC,
VeritasKarishma,
Bunuel,
chetan2u,
IanStewart,
ArvindCrackVerbal,
AaronPond,
GMATinsightIt seems that the current price could be also \($-4\). How the two different prices ($3 and $-4) effect whole the SAME scenario?
Thanks__
AsadWhen we get some results with quadratic, then we need to use the basic understanding of given variables
e.g. Price can NOT be negative
e.g. In work rate problems, the number of men/machines can NOT be negative and also can NOT be decimal numbers
Here we have to use the same logic and strike off the negative value and accept the positive possible values.
I hope this explains your doubt.
GMATinsightThank you for your helpful explanation. When I did the algebraic approach, I foiled and ended up getting:
pn - 10p + n=130
I then used the other equation pn=120 and substituted that in for pn, to get:
120 - 10p + n =130
To confirm my understanding, what I did was wrong because when factoring you want to substitute only in for ONE variable?
Yes, you should substitute one variable in form of other to get one equation in one variable and hopefully get only one acceptable solution,