The answer of the above equation is 81.

Explaination:

Let the red flower be, R

Let the blue flower be, B

& the yellow flower be, Y

Now, rewriting the above equations in the form of terms.

Equation(1); R + R + R = 60

Equation(2); R + B + B = 30

Equation(3); B – 2Y = 3

Equation(4); Y + R * B = ?

Now, initiating with equation(1);

R + R + R = 60

3R = 60

R = 20

Substituting the value of R in equation(2);

R + B + B = 30

20 + 2B = 30

2B = 10

B = 5

Similarly, substitute the value of B in equation(3);

B – 2Y = 3

5 – 2Y = 3

2Y = 2

Y = 1,

On closer observation, it is seen that the blue flower has only 4 petals and not 5! So the value of the blue flower in the last line cannot be the same as the value of the other blue flowers (5) as it is a completely different flower!

So, I will consider the value of the blue flowers to be the number of petals. This means I am looking for the value of petals in the equation since petals and not flowers are used in the final equation.

Therefore, if blue a flower has 5 petals, it implies a petal = 1. 

So for final equation(4), the value of a blue flower with 4 petals will be 4.

Final equation ;

Y + R * B = ?

= 1 + 20 * 4

= 81

Y + R * B = 81