We will assume that the original price before price reduction =  x

The price was decreased by 22%

Then the price after sale = The original [price - the amount reduced

                                      =   x - (22% x)  = 30

But given that the vurrent price ( after reductions) = $ 30

Then we will write:

 x - 22%*x = 30

But 22% = 22/100 = 0.22

==> x - 0.22 x = 30

==> 0.78 x = 30

Now we will divide by 0.78

==> x = 30/ 0.78 = 38.46 ( approx.)

Then the original price of the trousers was = $ 38.46