First we calculate for the total number of possibilities

(permutation) to select 4 disks from the container:

Total number of possibilities = 10 * 9 * 8 * 7

**Total number of possibilities = 5040**

Now let us find the 4 disks that will result in a range of 7.

Range = highest number – lowest number

The pair of highest and lowest number that will result in

range of 7 is: (1 & 8), (2 & 9), (3 & 10)

As a basis of calculation, let us use the pair 1 & 8.

There are four possible ways to select 1 and three for 8.

Arrangements of maximum and minimum pair = 4 * 3

**Arrangements of maximum and minimum pair=12**

Now we need to calculate for the remaining 2 disk. There

are 6 numbers between 1 & 8. The total possibilities for selecting 2 disk

from the remaining 6 is:

Possibilities of selecting 2 disk from remaining 6 = 6 *

5

**Possibilities of selecting 2 disk from remaining 6 = 30**

Therefore, the total possibility to get a range of 7 from

a pair of 1 & 8 is:

Total possibility for a pair = 12 * 30

**Total possibility for a pair = 360**

Since there are a total of three pairs (1 & 8), (2

& 9), (3 & 10):

Total possibilities of the 3 pairs = 360 * 3

**Total possibilities of the 3 pairs = 1080**

Therefore:

Probability = Total possibilities of the 3 pairs / Total

number of possibilities

**Probability**

= 1080 / 5040 = 3 / 14 (FINAL

ANSWER)