Question

A box has 5 beads of the same size, but all are different colors. Tina draws a bead randomly from the box, notes its color, and then puts the bead back in the box. She repeats this 3 times. What is the probability that Tina would pick a red bead on the first draw, then a green bead, and finally a red bead again?

Answers:
1/625, 1/180, 1/150, 1/125

please help me understand I have no idea how to do this

Answer 1

ok so do you understand probability

Answer 2

yes mostly

Answer 3

ok ok so there are 5 beads of the same size in the box all in different colors

Answer 4

she draws a bead 4 times

Answer 5

and there are 5 beads out of the four times she draws a bead which means it is 4/5

Answer 6

now find a fraction equivalent to that

Answer 7

a fraction equivalent would be like 8/10 but the answers are all 1 as the numerator and then a big number as the denominator

Answer 8

the probability of picking any one bead is 1 out of 5. since the bead is replaced each time then the probabilty of choosing any of the beads for the next pull is still 1/5

Answer 9

1/5 * 1/5 * 1/5 seems to make the most sense to me

Answer 10

spose there is no replacement

the probability of pulling a red first is 1/5
the probability of then pulling a green is 1/4
the probability of pulling a red next is 0

but since we replace the bead each time the probability of pulling any bead remains 1 out of 5 for any given pull