Question

if the price of pen is reduced by 25% a person can buy 2 more pens for a rupee. how many pens are available for one rupee​

Answer 1

Answer:

Price(P) x Q(Quantity) = E(Expenditure)

If E is constant, a reduction of 25% or 1/4th in P will result in increase of 1/(4-1) or 1/3rd in Q.

This is a rule.

=> 1/3Q = 2

=> Q = 6

Justification :

Let unit price = Rs 100 & Quantity purchased = 30 pieces

Expenditure = 100 x 30 = 3000

If price reduce by 25% or 1/4th, new unit price = Rs 75

If expenditure remains constant at Rs 3000, revised quantity = 3000/75 = 40

Thus, there is an increase of 40 - 30 = 10 units or 1/3rd increase in quantity.

Answer 2

Given:

Price of pen is reduced by 25%,a person can buy 2 more pens for a rupee.

To find:

How many pens are available for 1 rupee​

Solution:

From the given information, we have the data as follows.

Price of pen is reduced by 25%,a person can buy 2 more pens for a rupee.

Let the total number of pens be "n".

As, the price of the pen is reduced by 25%, so, the current price of the pens is,

Reduced price = 75/100 × 1 = 3/4

For 3/4 rupees, we get "n" pens.

For 1 rupee, we get (n × 4/3) pens.

Therefore, we have,

4n/3 = n + 2

4n = 3n + 6

n = 6

Therefore, the total number of pens that can be bought for 1 rupee are,

= 6 + 2

= 8

Therefore, 8 pens are available for 1 rupee​.