She wants to use 3/4 of the recipe and 3/4 of a cup 4 times equals three cups. Three cups is 3/4 of 4 cups.
When a pen is sold at a discount of 15% there is a gain of rs 10
When the pen is sold at 25% discount there is a loss of rs 2
Therefore the mark price of the pen can be calculated as follows
15% = c.p + 10 rs
25 % = c.p - 2 rs
25%-15% = 10 rs +2 rs
10% = 12 rs
10/100 = 12 rs
0.1= 12 rs
12/0.1
= 120 rs
Hence the mark price of the pen is 120 rs
