Question

the ratio of prices of cello and rotomac pens in 2000 were in the ratio of 3:5.In 2005 the price of cello pen trebles itself and the price of rotomac pen is incresed by rs100 ,then the new ratio of the price of the same pen becomes 4:5 .what was the original price of the rotomac pen in 2000​

Answer 1

Answer:

80 rupees

Step-by-step explanation:

In 2000,

Price of Cello : Price of Rotomac Pen

= 3 : 5

Let,

the Price of Cello in 2000 was 3x

and, the Price of Rotomac pen was 5x

In 2005,

The price of Cello is trebled and the price of Rotomac pen is increased by 100 rs.

so,

the new price of Cello is = 3 × 3x = 9x

the new price of Rotomac is = 5x + 100

So, according to the question, we get :

$9x \: \colon (5x + 100) = 4 \: \colon \: 5 \\ = > \: \frac{9x}{(5x + 100)} = \frac{4}{5} \\ = > \: 9x \: \times \: 5 = 4 \: \times \: (5 x + 100) \\ = > \: 45x \: = \: 20x \: + 400 \\ = > \: 45x \: - \: 20x \: = \: 400 \\ = > 25x = 400 \\ = > x \: = \frac{400}{25} \\ = > x = 16$

So, the price of Rotomac Pen in 2000 was :

$5x \: = 5 \times 16 = 80 \: rupees$