Given:
In an asteroid field, 75% of the asteroids are carbonaceous asteroids.
There are 375,000 carbonaceous asteroids in the asteroid field.
To find:
The number of asteroids that are not carbonaceous.
Solution:
Let the total number of asteroids be x.
According to question,
[tex]75\%\text{ of }x = 375000[/tex]
[tex]\dfrac{75}{100}x=375000[/tex]
[tex]0.75x=375000[/tex]
Divide both sides by 0.75.
[tex]x=\dfrac{375000}{0.75}[/tex]
[tex]x=500000[/tex]
Asteroids not carbonaceous = Total asteroids - Carbonaceous asteroids
[tex]=500000-375000[/tex]
[tex]=125000[/tex]
Therefore, 125,000 asteroids are not carbonaceous.