Answer: 1/4
Step-by-step explanation: To find out what fraction of Cathy's garden is planted with red flowers, we need to multiply the fraction of the garden planted with flowers (5/6) by the fraction of the flowers that are red (3/10).
First, let's multiply the numerators together: 5 * 3 = 15.
Next, let's multiply the denominators together: 6 * 10 = 60.
So, the fraction of Cathy's garden that is planted with red flowers is 15/60.
To simplify this fraction, we can divide both the numerator and denominator by their greatest common divisor, which is 15. When we do that, we get:
15 ÷ 15 = 1
60 ÷ 15 = 4
Therefore, the simplified fraction is 1/4.
In conclusion, 1/4 of Cathy's garden is planted with red flowers.