Answer:
13
![(1)/(3)](https://img.qammunity.org/2022/formulas/mathematics/high-school/8c4su5tuu474mta5yxnqkrtvi2n4u8590o.png)
Explanation:
Firstly, we need to calculate the ratio of cup a to cup b:
![(1)/(2) : 1 (2)/(3)](https://img.qammunity.org/2022/formulas/mathematics/college/vhldmys4bczsb40yn02yu5uc4qycyobbcr.png)
To find out how much of cup b we need after using 4 cups of cup a, we can divide 4 by the ratio of cup a:
4 ÷
= 8
So we need to multiply the ratio of cup b by 8:
8 *
= 13
![(1)/(3)](https://img.qammunity.org/2022/formulas/mathematics/high-school/8c4su5tuu474mta5yxnqkrtvi2n4u8590o.png)
Meaning that
13
cups of cup b is needed.
Hope this helps!