Answer:
$31.80
Step-by-step explanation:
First, find the sale price. 
Normally you pay for 100% of the price. Since it is 25% off, you only pay for 75% of the price. (100%-25%=75%)
Therefore, we can multiply 75% and $40
75% * $40 
Convert 75% to a decimal by dividing 75 by 100 or moving the decimal place 2 spots to the left. 
75/100=0.75
75.0 --> 7.5 --> 0.75 
0.75* $40 
Multiply 
$30 
Now, find the price with tax. 
You have to pay for 100% of the price, plus an additional 6% for the tax. Therefore, you are actually paying for 106% of the price (100% + 6% = 106%)
Therefore, we can multiply 106% and $30 
106% * $30 
Convert 106% to a decimal by dividing 106 by 100 or moving the decimal place 2 spots to the left. 
106/100=1.06 
106.0 --> 10.6 --> 1.06 
1.06 * $30 
Multiply 
$31.8 
Niko paid $31.80 for the game.