Question

135. If the cost price of 15 pens is equal to the selling price of 20 pens, then the loss
percent is
(a) 25%
(b) 20%
(c) 15%
(d) 18%​

Answer 1

Answer:

Answer is 25 %

Step-by-step explanation:

If the cost price of 15 pens is equal to the selling price of 20 pens,

Let the cost price of each one be ₹x and the selling price of each pen is y.

Cost price of 15 pen = 15 × x = 15x

Selling price of 20 pen = 20 × y = 20y

As per statement :

15x = 20y

y = 15x/20

y = 3/4×

y = 0.75x

Loss percentage = (Cost price - sale price)/Cost price ×100

Loss % = (x - 0.75x)/x ×100

Loss % = 0.25x/x × 100

Loss % = 0.25 × 100

Loss % = 25%

Answer the percentage loss is 25 percent

Answer 2

Given :

• Cost price of 15 pens = Selling Price of 20 pens

To find :

Loss percentage

Formula used :

• Loss = CP - SP
• Loss% = [ Loss × 100 ] ÷ CP

Let -

• CP of one pen = x
• SP of one pen = y

Solution :

CP of 15 pens = SP of 20 pens

➝ 15 × CP of one pen = 20 × SP of one pen

➝ 15x = 20y

➝ y = 15x ÷ 20

➝ y = (3/4)x

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Now we know that ,

• CP of one pen = x
• SP of 1 pen = y = (3/4)x

$\sf \implies \: Loss \: = x - \dfrac{3}{4} x \\ \\ \sf \implies \: Loss \: = \: \dfrac{(x \times 4) - (3x \times 1)}{4} \\ \\ \sf \implies \: Loss \: = \dfrac{4x - 3x}{4} \\ \\ \sf \implies \: Loss \: = \: \dfrac{x}{4}$

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$\sf \implies \: Loss\:\%\:=\: \dfrac{ \dfrac{x}{4} }{x} \times 100 \\ \\ \sf \implies \: Loss\:\%\:=\: \dfrac{x}{4} \times \dfrac{1}{x} \times 100 \\ \\ \sf \implies \: Loss\:\%\:=\: \dfrac{100}{4} \: \%\:\: \\ \\ \sf \implies \: Loss\:\%\:=\:25\%\:$

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ANSWER :

Option (a) 25%