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: 12 acres could be planted (at most)
Step-by-step explanation: Since there will be twice as many acres of wheat in comparison to the corn, out of the total 36 acres at least 24 of those will need to be wheat. That leaves 12 acres left for the corn.
For this we almost have the following equation:

We must match the equation to zero:

From here, we clear the value of t.
We have then:

We discard the negative root because we are looking for time:
Answer:
it will take him to reach the ground about:

seconds
Answer:
your answer is true.
Step-by-step explanation:
As 8 is in the hundredth place.