Process costing

Hi

4000Kg of raw material are input to a chemical process. Normal losses are expected to be 10% of input and because of their toxic nature will incur a disposal cost of $2 per kg.
The Process cost $11800 and actual output was 3550kg.

What is the total cost of abnormal loss(to the nearest $)?

A. $53
B. $153
C. $175
D. $275

solution:

cost per unit = 11800+(400X2)/3,600 = $3,5
Abnormal loss = 3,600-3,550 = 50kg
Cost of abnormal loss = 50X3,5=175

but the answer is 275.

they calculated the last one like this 50X3,5X2= 275

And I don’t get it why… I assume this is because every loss (despite the fact it’s normal or abnormal) costs 2$? Am I right?

thanks in advance