Answer:
(a) 720 ways
(b) 120 ways
(c) 24 ways
Step-by-step explanation:
Given

--- number of letters
Solving (a): Number of arrangements.
We have:

So, the number of arrangements is calculated as:

This gives:

This gives:


Solving (b): DA as a unit
DA as a unit implies that, we have:
[DA] N C E R
So, we have:

So, the number of arrangements is calculated as:

This gives:

This gives:


Solving (c): NCE as a unit
NCE as a unit implies that, we have:
D A [NCE] R
So, we have:

So, the number of arrangements is calculated as:

This gives:

This gives:


Answer: 15
Step-by-step explanation:
Lets name the missing point as "x"
8^2 + x^2 = 17^2
=> 64 + x^2 = 289
=> x^2 = 289 - 64
=> x^2 = 225
=> x = 15
Angle ABC=DEF then
Side AB=DF
Side BC=EF
and Side CA=FD
So if side ac=DF
side DF=6cm.
Supplementary angles are 180 in total, so to find the answer you do 180-10, which equals 170. The answer is 170