Yesterday, the snow was 2 feet deep in front of archie’s house. today, the snow depth dropped to 1.6 feet because the day is so warm. what is the percent change in the depth of the snow?

Earlier snow depth = 2 feet
later snow depth = 1.6 feet

change 
2 - 1.6
0.4 feet

percentage change
(0.4 / 2) * 100
20 %

The correct answer of this question is 20%.
The given values are the initial depth of snow which is 2 feet and the final depth which is 1.6 feet.
The solution of the problem is:
2 ft. - 1.6 ft. = 0.4 ft.
0.4 ft. / 2 ft. = 0.2
To calculate for the percentage,
0.2 x 100% = 20%

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.