Hello,
please try to solve these questions
Hello, m777!
If that's really an upper-case X in (3), the answer is (4) "none of these".a) Which of these is true?
1) {x} ε {x}
2) φ ε {x}
3) {X} ε {{x}}
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?
The answer is (2).
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?
The answer is (2).
I'm not familiar with "binary trees" . . . sorry.