Selina solutions

# Question 11

Q11) 40 pens are bought at 4 for Rs. 50 and all of them are sold at 5 for Rs. 80

Find :

(i) C.P. of one pen.

(ii) S/P. of one pen.

(iii) Profit made by selling one pen.

(iv) Profit percent made by selling one pen.

(v) C.P. of 40 pens

(vi) S.P. of 40 pens.

(vii) Profit made by selling 40 pens.

(viii) Profit percent made by selling 40 pens. Are the results of parts (iv) and (viii) the same? What conclusion do you draw from the above result?

Solution:

(i) CP of 4 pen= Rs. 50

∴ CP of 40 pens = \frac{50\times40}{4}=Rs.500

And CP of 1 pen = \frac{500}{40}=Rs.\frac{25}{2}=Rs.12.50

(ii) SP of pens = Rs. 80

∴ SP of 1 pen = \frac{80}{5}=Rs.16

(iii) Profit pn 1 pen = SP - CP

=Rs. 16.00 - 12.50 = Rs. 3.50

(iv) Profit percent = \frac{\Pr ofit\times100}{CP}=\frac{3.50\times100}{12.50}=\frac{350\times100}{1250}=28\%

(v) CP of 40 pens = 40 x 12.50 = Rs. 500

(vi) SP of 40 pens = 40 x 16 = Rs. 640

(vii) Profit on 40 pens = SP - CP

= 640 - 500 = Rs. 140

(viii) Profit on 40 pens = \frac{\Pr ofit\times100}{CP}=\frac{140\times100}{500}=28\%

Yes, the results of (iv) and (viii) are the same.

We see that the profit of an equal number of articles remains the same.

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