Answer:
a. 15 Jellybeans.
Step-by-step explanation:
Let "a pocketful of jelly beans" = x jelly beans.
"She gave half of them to her friend Marcus"
Now she has x/2 jelly beans left.
"and then a third of what she had left to Shelby"
If she gives away 1/3 of an amount, she has left 2/3 of the amount.
Now she has (2/3)(x/2) = x/3
She now has 1/3 of the original amount.
"Finally, she and her sister each ate five jellybeans and no jellybeans remained."
They ate a total of 10 jelly beans, and none were left.
The amount remaining, x/3 was 10.
x/3 = 10
Multiply both sides by 3:
x = 30
She started with 30 jellybeans.
"She gave half of them to her friend Marcus"
30/2 = 15
Answer: a. 15 Jellybeans