Answer:
25 times less than the Moon's mass
Step-by-step explanation:
The asteroids are small, rocky objects that orbit the Sun. Although asteroids orbit the Sun like planets, they are much smaller than planets.
There are millions of boulder-size and larger rocks that orbit the Sun, most of them between the orbits of Mars and Jupiter.
The largest asteroid is Ceres with a diameter of 1000 kilometers. Pallas and Vesta have diameters of about 500 kilometers and about 15 others have diameters larger than 250 kilometers
Although in the Solar System there are millions the asteroids, the combined mass of all of the asteroids is about 25 times less than the Moon's mass.
Then the answer for your question is:
25 times less than the Moon's mass
bibliographic source: www.astronomynotes.com