Correct option is A
Given:
Buttons bought at 22 for a Rupee
Formula Used:
Gain% =
Gain = SP - CP
Solution:
Cost price for 22 buttons = Rs 1
For a gain of 10%, 22 buttons should sell for 1 + 10% of 1
So, SP of 22 buttons = Rs
For Rs buttons sold are 22
For Rs.1 buttons sold = = 20
Thus, To gain 10% , vendor should sell 20 buttons for Rs 1.