Question

If price of 1 dozen pen is recuced by Rs 6 , then 3 more pens will got in Rs 30 .Before the reduction of price, calculate the price of 1 dozen pen?​

Answer 1

Answer:

1dozen=12pc

cost of 12pc pen

=12*6=Rs36

Answer 2

Answer:

Given :-

• If the price of 1 dozen pen is reduced by Rs. 6, then 3 more pens will be got in Rs. 30. Before the reduction of price.

Find out :-

• Let us calculate the price of 1 dozen pen.

Solution :-

Present price of every dozen of pen is Rs. x.

∴ In Rs. 30 number of pen can be obtained = 30/x

When the price is reduced by Rs. x then price per dozen will be Rs. (x - 6)

∴ In Rs. 30 number of pen = 30/x - 6

According to the question,

✯ 30/x - 6 - 30/x = 3/12

➻ 30x - 30(x - 6)/x(x - 6) = 1/4

➻ 30x - 30x + 180/x(x - 6) = 1/4

➻ 180/x(x - 6) = 1/4

➻ x² - 6x = 720

➻ x² - 6x - 720 = 0

➻ x² - 30x + 24x - 720 = 0

➻ x(x - 30) + 24(x - 30) = 0

➻ (x - 30) (x + 24) = 0

➻ (x - 30) = 0

➻ x - 30 = 0

➻ x = 30

Either,

➻ (x + 24) = 0

➻ x + 24 = 0

➻ x = - 24

x ≠ - 24 because price is not negative

∴ x = 30

∴ Price of every dozen of pen is Rs. 30.