21.A bookseller sells a book at a gain of 10%. If he had bought it at

1.	21.A bookseller sells a book at a gain of 10%. If he had bought it at 4% less sold it for RS 6 more,he would have gained 184% . The cost price of the book isÎą) Rs 130b) Rs 140c) Rs 150d) Rs 160
Answer» Let the C.P of the book= ₹ x gain = 10% S.P =110x/ 100 If he had bought it at 4% less and sold it for Rs 6 more, C.P=96x/ 100 S.P =(110x/100)+6 Gain=((110x/100)+6)− 96x/100 = (14x/100)+6 Now, the gain=18 3/4%=75/ 4% Therefore, (14x/100)+6=(96x/100)×75/400 (14x/100)+6=(96x/4)×3/ 400 14x+600=(96x/ 4)×3/ 4 14x+600=6 x(×3) 14x+600=18x 18x-14x=600 4x=600 x=150 The C.P of the book is ₹ 150

21.A bookseller sells a book at a gain of 10%. If he had bought it at 4% less sold it for RS 6 more,he would have gained 184% . The cost price of the book isÎą) Rs 130b) Rs 140c) Rs 150d) Rs 160

Answer»

Let the C.P of the book= ₹ x

gain = 10%

S.P =110x/ 100

If he had bought it at 4% less and sold it for Rs 6 more,

C.P=96x/ 100

S.P =(110x/100)+6

Gain=((110x/100)+6)− 96x/100

= (14x/100)+6

Now, the gain=18 3/4%=75/ 4%

Therefore,

(14x/100)+6=(96x/100)×75/400

(14x/100)+6=(96x/4)×3/ 400

14x+600=(96x/ 4)×3/ 4

14x+600=6 x(×3)

14x+600=18x

18x-14x=600

4x=600

x=150

The C.P of the book is ₹ 150