There are 20 jellybeans remaining after the 6 orange and 4 pineapple jellybeans have been eaten. Therefore 10 of the 20 remaining jellybeans must be raspberry. So there is a 1 in2 chance that the next one picked will be raspberry.
The answer is 8. This is because when you substitute 8 with “a” you then solve the problem to see if it is equal to the answer. -4+8=4... -4+4=0 so that is wrong and -4+O=-4 which is also incorrect.