Question 161224
To find the answer you must first find out what 4% of $2100 is...

.04 x 2100 = 84

Since the question only asks how much tax you will pay...the answer is $84.

A different way to figure it out is to realize that if you need to find 4% of $2100...that's the same as needing to find out "what" x 25 will equal $2100.  This is because 4% goes into 100% 25 times. From this information we could get the equation...

25x = 2100

Divide both sides by 25...

x = 2100/25
x = 84