A sells a mixer to B at 20% loss and B sells it to C at 15% profit. C sells it to D at 15% profit. If the difference between C.P. of A and C.P. of D is Rs.145, what is the C.P. in (Rs.) for A?

Let's solve this step by step:

Step 1: Let's assume the cost price for A is Rs. x.

Step 2: A sells the mixer to B at a 20% loss. So, the selling price for A (which is the cost price for B) will be 80% of x. This can be calculated as (80/100)*x = 0.8x.

Step 3: B sells the mixer to C at a 15% profit. So, the selling price for B (which is the cost price for C) will be 115% of 0.8x. This can be calculated as (115/100)*0.8x = 0.92x.

Step 4: C sells the mixer to D at a 15% profit. So, the selling price for C (which is the cost price for D) will be 115% of 0.92x. This can be calculated as (115/100)*0.92x = 1.058x.

Step 5: According to the problem, the difference between the cost price of A and the cost price of D is Rs. 145. So, we can set up the equation x - 1.058x = 145.

Step 6: Solving this equation gives us x = 145 / (1 - 1.058) = -7250.

However, the cost price cannot be negative. This means there might be a mistake in the problem statement. The difference between the cost price of A and D should be the cost price of A is more than the cost price of D. If we consider this, the equation becomes x - 1.058x = -145.

Step 7: Solving this equation gives us x = -145 / (1 - 1.058) = 7250.

So, the cost price for A is Rs. 7250.