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: 60
Step-by-step explanation:
Let the side lengths of the rectangular pan be m and n. It follows that (m-2) (n-2)=
So, since haf of the brownie pieces are in the interior. This gives 2 (m-2) (n-2) =mn
mn- 2m - 2n- 4 = 0
Then Adding 8 to both sides and applying, we obtain (m-2) (n-2) =8
Since now, m and n are both positive, we obtain (m,n) = (5,12), (6,8) (up to ordering). By inspection, 5. 12 = 60
which maximizes the number of brownies in total which is the greatest number.
Hope that helped! =)