11)

If x² + 8y² + 12y - 4xy + 9 = 0, then the value of (7x + 8y) is:

SSC CPO 2020

A)

9

B)

-33

C)

-9

D)

33

12)

If a² + b² + c² + 84 = 4(a - 2b + 4c), then \(\sqrt {ab - bc + ca}\) is equal to:

SSC CPO 2020

A)

\(4\sqrt {10}\)

B)

\(5\sqrt {10}\)

C)

\(2\sqrt {10}\)

D)

\(\sqrt {10}\)

13)

If a³ + b³ = 217 and a + b = 7, then the value of ab is:

SSC CPO 2020

A)

-1

B)

6

C)

-6

D)

7

14)

If x + y + z = 13, x² + y² + z² = 133 and x³ + y³ + z³ = 847, then the value of \(\sqrt[3]{{xyz}}\) is:

SSC CPO 2020

A)

-9

B)

-6

C)

7

D)

8

15)

If (5√5x³ – 3√3y³) ÷ (√5x – √3y) = (Ax² + By² + Cxy), then what is the value of (3A – B – √15C) ?

SSC CPO 2020

A)

-5

B)

12

C)

8

D)

-3

16)

If x + y + z = 19, x² + y² + z² = 133 and xz = y², x > z > 0, what is the value of (x - z) ?

SSC CPO 2020

A)

-2

B)

-5

C)

5

D)

0

17)

X⁴ + X^-4 = 194, X > 0, then what is the value of X + \(\frac{1}{X}\) + 2 ?

SSC CPO 2020

A)

14

B)

4

C)

8

D)

6

18)

If a + b + c = 0, then the value of \(\frac{{a^2}}{{bc}} +\)\(\frac{{b^2}}{{ac}} +\)\(\frac{{c^2}}{{ab}} \) is:

SSC CPO 2020

A)

1

B)

0

C)

-1

D)

3

19)

If a² + b² = 82 and ab = 9, then a possible value of a³ + b³ is:

SSC CPO 2020

A)

750

B)

730

C)

830

D)

720

20)

In a school, 5/12 of the number of students are girls and the rest are boys. 4/7 of the number of boys are below 14 years of age, and 2/5 of the number of girls are 14 years or above 14 years of age. If the number of students below 14 years of age is 1120, then the total number of students in the school is:

SSC CPO 2020

A)

1820

B)

1290

C)

1920

D)

1900