A wholesaler purchased 7 hair clips for a rupee. How many for a rupee must he sell to get profit of 40%?

Step 1: First, we need to find out the cost price of each hair clip. The wholesaler purchased 7 hair clips for a rupee, so the cost price of each hair clip is 1/7 = 0.14 rupees.

Step 2: The wholesaler wants to make a profit of 40%. So, the selling price of each hair clip should be 140% of the cost price.

Step 3: To calculate the selling price, we multiply the cost price by 140%. So, 0.14 * 140/100 = 0.196 rupees.

Step 4: Now, we need to find out how many hair clips the wholesaler can sell for a rupee to get this selling price. So, 1/0.196 = approximately 5.1.

Since the wholesaler can't sell a fraction of a hair clip, he must sell 5 hair clips for a rupee to get a profit of 40%.