A Bag contains eight red marbles and eight blue marbles. You randomly pick a marble and then return it to the bag before picking another marble. Both the first and second marbles are red.

1/4

Step-by-step explanation:

A bag contains a total of 16 marbles

Red marbles = 8

Blue marbles = 8

The question says you pick randomly one marble and you return before picking another marble , which means, there is replacement.

Probability of picking the first red marble = 8/16

Probability of picking the second red marble = 8/16

Probability that both the first and second marble is red = 8/16 × 8/16

= 64/256 = 1/4

Therefore, the probability that both the first and second marbles are red = 1/4

step-by-step explanation:

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons