A shopkeeper sells a mattress and makes a profit of 10% on the cost price. If he had sold the mattress for $150 less,he would have incurred a loss of 40% on the cost price. Find the cost price of the mattress.

1.1c - 150 = 0.6c

c = 300

To find the cost price of the mattress, we can use the information given about the profit and loss percentages.

Let's assume the cost price of the mattress is x dollars.

According to the given information, the shopkeeper sells the mattress with a 10% profit. Therefore, the selling price would be 110% of the cost price.
So, the selling price of the mattress is 1.1 * x dollars.

If the shopkeeper had sold the mattress for $150 less, he would have incurred a loss of 40% on the cost price. This means that the selling price would be 60% of the cost price.
So, the selling price of the mattress in this case is 0.6 * x dollars.

From the above information, we can set up the following equation:

1.1 * x - $150 = 0.6 * x

Now, let's solve this equation to find the cost price (x).

1.1x - $150 = 0.6x

0.5x = $150

x = $150 / 0.5

x = $300

Therefore, the cost price of the mattress is $300.