# Discrete Mathematics Week 0 Assignment 0

These are answers for NPTEL Discrete Mathematics Week 0 Assignment 0

1. If f(x)=2x+20/x−2, g(x)=2x−3f(x)=2x+20x−2, g(x)=2x−3 then f(g(3))f(g(3)) is______

3

13

26

49

2. How many three digit numbers greater than 500 can be formed using numbers 1,3,5,7,9, without repetition?

24

36

16

48

3. The coefficient of x^4y^2x^4y^2 in the expression (4x2y+24)3(4x2y+24)3 is equal to ______ .

64

1152

6912

13824

4. Let 𝑃 be set of prime numbers and 𝑍 be set of integers, then 𝑃 ∩ 𝑍 will be?

𝑃 ∩ 𝑍 = {0,1,2,3,5,7,11,13,17,19…….}

𝑃 ∩ 𝑍 = {3,5,7,11,13,17,19…….}

𝑃 ∩ 𝑍 = {2,3,5,7,11,13,17,19…….}

𝑃 ∩ 𝑍 = {1,2,3,5,7,11,13,17,19…….}

5. Which of the following is an empty set?

{x: x is a even prime greater than 3}

{x | x ∈ Z; -1 ≤ x ≤ 1}

{x: x is an odd prime number less than 5 }

{ϕ}

These are answers for NPTEL Discrete Mathematics Week 0 Assignment 0

6. Which of the following is a rational number(s)?

e

π

√2

√64/√25

7. A dice is thrown in the air. The probability of getting odd numbers is

1/2

1/3

1/6

2/5

8. The sum of two numbers is 27 and the product is 182. The numbers are:

12 and 13

13 and 26

13 and 14

12 and 15

9. Let f:R→Rf:R→R be defined by

f(x)=⎧⎩⎨2x;x2;3x;x>31<x<3x≤3f(x)={2x;x>3×2;1<x<33x;x≤3

Then f(−1)+f(2)+f(4)

9

14

5

12

10. If x+1x=2,x+1x=2, then what will be the value of x7+1×7?

1

2

7/2

7