Question

40 pens are bought at 4 for ₹50 and all of them are sold at 5 for ₹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.​

Answer 1

Step-by-step explanation:

i) cost of 4 pens = 50

cost of 1= 50/4

             = ₹12.5

ii) S.P. of 5 pens=80

S.P. of 1 pen=80/5

                   =₹16

iii)Profit= S.P.-C.P.     (of 1 pen)

           = 16-12.5

           =₹3.5

iv)Profit % =$\frac{profit}{C.P.}$ X 100     (of 1 pen)

                = $\frac{3.5}{12.5}$ X100

                =₹28  

v) Cost of 1 pen= 12.5

Cost of 40 pens=12.5 X40

                         =₹500

vi) S.P. of 1 pen= 16

S.P. of 40 pens= 16 X 40

                        = ₹640

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

            =640-500

            =₹140

viii)Profit%= $\frac{profit}{C.P.}$ X 100     (of 40 pens)

                = $\frac{140}{500}$ X 100

                = 28%

        Hope it helps you!!