Numbered disks are placed in a box and one disk is selected at random. If there are 6 red disks numbered 1through 6, and 4 yellow disks numbered 7 through 10, find the probability of selecting a yellow disk, given thatthe number selected is less than or equal to 3 or greater than or equal to 8.
A) $\frac { 1 } { 2 }$
B) $\frac { 3 } { 4 }$
C) $\frac { 3 } { 5 }$
D) $\frac { 3 } { 10 }$

Question

Numbered disks are placed in a box and one disk is selected at random. If there are 6 red disks numbered 1through 6, and 4 yellow disks numbered 7 through 10, find the probability of selecting a yellow disk, given thatthe number selected is less than or equal to 3 or greater than or equal to 8. 
A) $\frac { 1 } { 2 }$
B) $\frac { 3 } { 4 }$
C) $\frac { 3 } { 5 }$
D) $\frac { 3 } { 10 }$

Quizplus · Accepted Answer

The disks that are either less than or equal to 3 or greater than or equal to 8 are 1, 2, 3, 8, 9, 10. Out of these, 3 are yellow (8, 9, 10), and 3 are red (1, 2, 3), making the probability of selecting a yellow disk 3 out of 6, or $\frac{1}{2}$.

Numbered Disks Are Placed in a Box and One Disk 12\frac { 1 } { 2 }21​

Numbered Disks Are Placed in a Box and One Disk $\frac { 1 } { 2 }$