Question

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) same? What conclusion do you draw from the above result?

Answer 1

(i) C.P. of 4 pens = Rs. 50

∴ C.P. of 40 pens = `(50 xx 40)/4` = Rs. 500

and C.P. of 1 pen = `500/40` = Rs. `25/2` = Rs. 12.50

(ii) S.P. of pens = Rs. 80

∴ S.P. of 1 pen = Rs. `80/5` = Rs. 16

(iii) Profit on one pen = S.P. - C.P.

= Rs. 16.00 - 12.50

= Rs. 3.50

(iv) Profit percent = `("Profit" xx 100)/"C.P."`

`= (3.50 xx 100)/12.50 = (350 xx 100)/1250 = 28%`

(v) C.P. of 40 pens = 40 × 12.50 = Rs. 500

(vi) S.P. of 40 pens = 40 ×16 = Rs. 640

(vii) Profit on 40 pens = S.P. - C.P.

= Rs. 640 - 500

= Rs. 140

(viii) Profit on 40 pens = `("Profit" xx 100)/"C.P."`

`= (140 xx 100)/500 = 28 %`

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

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