Help please. Need a simple explanation.

B) 20

Step-by-step explanation:

Each number in the equation needs to be a whole number, since you can't have 2.5 marbles or something like that.

2/5 of 16 is 6.4

2/5 of 20 is 8

2/5 of 21 is 8.4

2/5 of 26 is 10.4

Even though 20 is the only one that works, if you wanted to be sure it's right, just divide by three after subtracting 8 (the three remaining marbles.)

20-8=12

12÷3=4

The three remaining numbers would be equal and the amount of yellow numbers is a whole number. 20 is correct

Please give brainliest if I helped! :)

b