X purchased some pens for TK. 120 . If the price per piece of pen was TK. 3 less, he would have received 2 more pens. How many pens did he purchase ?

X purchased some pens for TK. 120 . If the price per piece of pen was TK. 3 less, he would have received 2 more pens. How many pens did he purchase ? Correct Answer 8

Let the number of pens be N. Then, price of each pen = 120/N He would get (N + 2) pens if the price of each pen was [120/N - 3]. So,  120 / (N + 2) = (120/N) - 3 or,  120 / (N + 2) = (120 - 3N) / N or,  120N = (120 - 3N) (N + 2) or,  120N = 120N + 120 x 2 - 3N2 - 3N x 2 or, 3N2 + 6N + 120N - 120N - 240 = 0 or, 3N2 + 6N - 240 = 0 or, N2 + 2N - 80 = 0 or, N2  + 10N - 8N  - 80 = 0 or, N(N + 10) - 8(N + 10) = 0 or, (N + 10) (N - 8) = 0 or, N - 8 = 0 [N + 10 = / 0] So, N = 8
Bissoy MCQ

Related Questions

At a stationary shop, it costs Tk. 185 for 4 gel-pen, 8 ball -point pens and 1 marker pen and Tk. 315 for 7 gel-pens, 15 ball point pens and 1 marker pen. What would be the cost of 1 gel-pen, 1 ball -point pen and 1 marker pen?
Maria purchased brand X pens for TK. 4.00 a piece and brand Y pens for TK. 2.80 a piece. If Maria purchased a total of 12 of those pens for TK. 42.00, how many brand X pens did she purchase ?
The price of a pen is 25% more than the price of a book . The Price of a pen holder is 50% more than the price of the book. How much is the price of the pen holder more than the price of the pen?
The price of a pen is 25% more than the price of a book. The price of a pen holder is 50% more than the price of the book. How much is the price of the pen holder more than the price of the pen?
A trader purchased some pens for Tk. 150. If the price of each pen was Tk. 5 less, he would have got 5 more pens. How many pens did he buy?
Maria Purchased brand X pens for Tk. 4.00 apiece and brand Y pens for Tk. 2.80 apiece. If Maria purchased a total of 12 of those pens for Tk. 42.00 ,how many brand x pens did she purchase?
Halim purchased brand A pen for Taka 200 each and brand B per for Taka 100 each. If he purchased a total of 8 of these pens for Taka 1,200 how many pens of brand A did he purchased ?
The price of a pen is 25% more than the price of a book. The price of a fan holder is 50% more than the price of the book. How much is the price of the pen holder more than the price of the pen?
If the price of pen is discounted by 40%, for Tk. 120 you can buy 4 more pens than you could buy at the original price. How many pens could be bought for Tk. 120 at the original price?
A retailer buys pens in packs of 24 for Tk.336/pack and then resells them in packs of 5 for Tk.80/pack. If the retailer sold all the pens it purchased and made a profit of Tk.960. How many packs of pens did the retailer purchase?