GMATPREP: Algebra

[cubicle_bound_misfit]

I did it taking help of Mr. Guess.
Please let me know the right approach.

regards,

[rosh26]

Hmm I would think this would be C or E - can any of the experts explain?

[albertrahul]

Answer is B.

Total amount spent = 130.
Information provided in question is that all pencils cost either 21 or 23 cents so only combination for pencils that produces 130 equals

(4*21) + (2*23) = 130

Hence 4 pencils for 23 cents each.

I'm sure there are algebraic ways of finding this answer, but since I'm not gud at algebra I preferred this way.

Take combination of last digits of price (21 & 23) to make 10 as end result. We however know that there are 6 pencils bought. 130/20 would give 6.x .