Question

By selling 10 dozen pencils, a shopkeeper gains the selling price of 40 pencils. Find his gain or loss per cent.

Answer 1

let the selling price of 1 pencil be Required
then SP of 10dzn ie 120 pencils=120rs
Gain =SP of 40 pencils=Rs40
CP=SP-PROFIT
=120-40=80

$gain\% = \frac{gain}{cp} \times 100 \\ \: \: \: \: \: \: \: \: \: \: = \frac{40}{80} \times 100 = 50$
Gain %=50%

Answer 2

Gain percentage is 33 1/3% or 33.33%

Given:

By selling 10 dozen pencils a shopkeeper gains the selling price of 40 pencils

To find:

Find his gain or loss percent

Solution:

Given number of pencils = 10 dozen = 10 × 12 = 120 pencils

By selling 120 pencils he gain selling price of 40 pencils

Let 1 Rs be the selling price of 1 pencil  

⇒ selling price of 40 pencils = 40 Rs

⇒ selling price of 120 pencils = 120 Rs

Given that on selling 120 the shopkeeper gain 40 Rs extra 120 Rs

⇒ Selling price of 120 pencils = 120 + 40 = 160

If 40 Rs is extra/gain cost price of 120 pencils = 120 Rs

Gain percentage = $\frac{40}{120} (100)$ = 33 1/3% or 33.33%

Gain percentage = $\frac{40}{120} (100)$ = 33 1/3% or 33.33%

Gain percentage is 33 1/3% or 33.33%

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