100 पेसिल को बेचने पर एक दुकानदार को 20 पेसिल के वि . मू . के बराबर लाभ होता है,  तो प्रतिशत लाभ ज्ञात करें

Options

A. 25
B. 20
C. 15
D. 12

Answer

A

Explanation

(a) Let SP of 1 Pencil is Rs. 1
SP of 100 pencil is Rs. 100
CP of 1 pencil is Rs. x
CP of 100 pencil is Rs. 100x
According to question,
Gain =SP -CP
20=100-100x
100x=80
`x=(80)/(100)=(4)/(5),x=(4)/(5)`
CP of 1 pencil = Rs. `(4)/(5)`
CP of 100 penci = Rs. `(4)/(5)xx100`=Rs. 80
SP of 100 pencils = Rs. 100
`:.` gain % `=(20)/(80)xx100=25%`