Ceres is an asteroid with a mass of 8.7 x 10^20 kg that is 2.767 AU from the Sun. How many kilometers away is it from the Sun?

In this problem the mass of the asteroid is completely irrelevant. To solve this we are going to take advantage of the fact the 1AU=149,598,000 kilometers, so we can establish a conversion factor as follows:
[tex]2.767AU* \frac{149598000km}{AU} =413937666[/tex]

We can conclude that the asteroid is 413,937,666 kilometers away from the sun, or in scientific notation 4.139376660·[tex]10^8[/tex] kilometers away form the sun.