Question

A stationer buys pens at 5 for Rs. 28 and sells them at a profit of 25%. How much should a customer pay, if

he buys

(i) only one pen

(ii) three pens ?​

Answer 1

Answer:

(ii) three pens.............

Answer 2

Question:

A stationer buys pens at 5 for Rs. 28 and sells them at a profit of 25%. How much should a customer pay, if he buys

(i) only one pen

(ii) three pens ?

To find?

• Sp of one pen
• Sp of three pens

Given:

• C.P of 5 pens = Rs 28
• Profit %= 25

Explanation :

So in question first it it is asked to find Selling price of 1 pencil . There are two methods to solve s. p if c.p and profit % is given. I have shown both the methods. In first method we have to find first profit by using formula of profit % ie p%=(p/c.p)*100 and then after getting profit applied this formula: (sp=c.p+p) to find s.p. Now in second method we can directly find s.p by using this formula: s.p=[(100+p%)/100]*c.p. And then in question it's asked to find s.p of three pens. For this ,just simply multiply c.p of 1 pen with 3.

Formula used:

• $\sf \: profit\% = \frac{profit}{cost \: price } \times 100$

• $\sf \: selling \: price \: of \: 1 \: pen = cost \: price + profit$

• $\sf \: s.p \: of \: one \: pen = \frac{100 + profit\%}{100} \times c.p \: of \: one \: pen$

• $\sf \: s.p \: of \: 3 \: pens = s.p \: of \: 1 \: pen \times 3$

Answer:

C.P of 5 pens = Rs 28

.°. C.P of 1 pen= Rs 28÷5

C.P of 1 pen =Rs 5.60

$\green{ \bold{part \: 1: }}$

To find S.P of 1 pen first we have to find Profit

So to find profit we have to use formula of profit %

$\sf \: profit\% = \frac{profit}{cost \: price } \times 100$

$:\implies \sf \: 25= \dfrac{profit}{5.6} \times 100$

$:\implies \sf \: profit = \dfrac{5.6 \times 25}{100}$

$:\implies \sf \: profit = \dfrac{56 \times { \cancel{25 }}^ { \: 1} }{ { \cancel{100}}^{ \: 4} \times 10}$

$:\implies \sf profit = \frac{14}{10}$

$:\implies\sf{profit = Rs \: 1.4}$

Finally we can find Selling price by putting this formula:

S.P= p+C.P

$\sf \: selling \: price \: of \: 1 \: pen = cost \: price + profit$

$:\implies\sf \: selling \: price \: of \: 1 \: pen = 5.6 + 1.4$

$:\implies \star \boxed{ \sf \: selling \: price \: of \: 1 \: pen= Rs \: 7} \star$

.°. Selling price of 1 pen=Rs 7

$\pink{ \underline{ \tt \: \pink{ \boxed{ \tt \:another \: method \: to \: solve \: value \: of \: s.p }}}}$

$\sf \: s.p \: of \: one \: pen = \frac{100 + profit\%}{100} \times c.p \: of \: one \: pen$

$:\implies \sf \: s.p \: of \: one \: pen = \frac{100 + 25}{100} \times 5.6$

$:\implies \sf \: s.p \: of \: one \: pen = \frac{125}{100} \times 5.6$

$:\implies\sf \: s.p \: of \: one \: pen = 5 \times 1.4$

$:\implies \star \boxed{ \sf \: s.p \: of \: one \: pen = Rs \: 7} \star$

$\green{ \bold{part \: 2: }}$

$\sf \: s.p \: of \: 3 \: pens = s.p \: of \: 1 \: pen \times 3$

$: \implies \sf \: s.p \: of \: 3 \: pens = 7 \times 3$

$: \implies \star \boxed{\sf \: s.p \: of \: 3 \: pens =Rs \: 21} \star$

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And all we are done! ✔

If it helped you then make a smile on your face :) ♡~