Answer:
Rita spend
of hour more on her chemistry assignment.
Explanation:
Fraction of an hour Rita spent on chemistry assignment =

Fraction of an hour Rita spent on math assignment =

∴ Fraction of hour Rita spent more on her chemistry assignment than math assignment
⇒

To subtract fractions we take LCD for 4 and 8. Since 8 is the least common multiple for 4 and 8 so, we take LCD= 8
To make the denominators same we need to multiply numerator and denominator of second fraction with 2.
⇒

⇒

After making the denominators common, we simply subtract numerators.
⇒

⇒

Therefore, Rita spend
of hour more on her chemistry assignment.