The city has 78 buses. 33% of them are new and cause less pollution. if the city replaces 15 old buses with new ones, what percent of the buses will be new?

78×.33=25.74 busses are new
25.74+15=40.74 new busses
78+15=93 total busses
40.74/78=0.5223076923= 52% will be new with the new 15 busses

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.