Solve the following picture puzzle:

Solution:

1. From the first equation, we can deduce the value of an apple. Since three apples add up to 9, one apple is equal to \( 9 / 3 = 3 \).
2. From the second equation, we know an apple is 3. So, \( 3 \times \text{banana} \times 3 = 36 \). This simplifies to \( 9 \times \text{banana} = 36 \), which means a banana is equal to \( 36 / 9 = 4 \).
3. From the third equation, we have an apple (3), a banana (4), and carrots. So, \( 3 \times 4 \times \text{carrots} = 144 \). This simplifies to \( 12 \times \text{carrots} = 144 \), meaning carrots are equal to \( 144 / 12 = 12 \).
4. The last equation has an apple (3), carrots (12), and a question mark (represented by an asterisk). The equation is \( 3 \times 12 + \text{asterisk} = 90 \). This simplifies to \( 36 + \text{asterisk} = 90 \), so the asterisk is equal to \( 90 - 36 = 54 \).

Answer: The asterisk represents the number 54.