Question

There are 12 beads in a box, some white and some black. The probability of drawing a white bead from it is 1/3.

a) How many white beads are there in the box?

b) How many black beads are there in the box?

c) If we take away two black beads from the box. What is the probability of drawing a white bead?​

Answer 1

Total number of beads =12

(a) Let the number of white beads be a.

Now. P (white bead) =

Total number of white bead/ Total number of beads =1/3

a/12=1/3

a=4.

Thus, there are 4 white beads in the box.

(b) Now, number of black beads =12-a=12−4=8.

(c) When two black beads taken away = 8-2=6

Total number of beads= 4+6=10

Now P(white bead) = 4/10= 2/5

Answer 2

Step-by-step explanation:

a)whitebeads=

3

1

of12

=

3

1

×12

=4

blackbeads=12−4

=8

b)blackbeadsleft=8−3=5

totalbeadsinbox=4+5=9

p(whitebead)=

9

4

c)blackbeadsleft=8+3=11

totalbeadsinbox=4+11=15

p(blackbead)=

15

11