# Math Help - mcqs

1. ## mcqs

Hello,
please try to solve these questions

2. Part 1)
False
True
True
False

Part 2)
The second one.

Part 3)
The third one.

Part 4)
Do not know.

3. Hello,
But i have to choose only one option in question no 1.i think so option no 3 is more suitable what is your point of view.

4. Originally Posted by m777
Hello,
But i have to choose only one option in question no 1.i think so option no 3 is more suitable what is your point of view.
In that case #3 is wrong. Because when you wrote {X} I was thinking you actually meant {x}. But since it matters here, it is wrong.

5. Hello, m777!

a) Which of these is true?

1) {x} ε {x}
2) φ ε {x}
3) {X} ε {{x}}
4) none of these
If that's really an upper-case X in (3), the answer is (4) "none of these".
If it's supposed to be "x" in there, the answer is (3).

b) In R, the symmetric property with respect to equality of numbers is:

1) .a = b . . b = -a
2) .a = b . . b = a
3) .a = b . . b = 2a
4) .a = b . . a = -b

Do you know what the symmetric property is?

Combination of n and k . . . that is: C(n,k)

. . . .n!
1) -------
. . (n-k)!

. . . . n!
2) ---------
. . k!(n-k)!

. . . . n!
3) ---------
. . n!(n-k)!

4) None of these

You're new to "combinations", aren't you?

I'm not familiar with "binary trees" . . . sorry.

6. Originally Posted by ThePerfectHacker
Part 1)
False
True
True
False
Option (2) is the statement: NullSet in {x}, which is false unless x=NullSet.

Option (3) is the statement: {X} in { {x} }, which is false unless there is a
convention in place that has X={x}.

But if options 1, 2, 3 are all false then 4 will be true.

RonL

7. d) There is a full binary tree that has 10 internal vertices and 13 terminal vertices

No, for a full binary tree:

n(terminal)=n(internal)+1

RonL

8. ## soroban

Hello,
Soroban.
yes, i have just started the topic "combinations". For any quantities a and b, if a = b, then b = a is symmetric property.