Square root and cube root

(16) What is the cube root of 125?

• (a) 5
• (b) 10
• (c) 15
• (d) 20

Answer

Correct Answer: (a) 5
The cube root of 125 is \( \sqrt[3]{125} = 5 \).
\sqrt[3]{125} = 5

(17) If the square of a number is 81, what is the cube root of that number?

• (a) 3
• (b) 9
• (c) 27
• (d) 81

Answer

Correct Answer: (d) 81
If the square of a number is 81, then the number itself is \( \sqrt{81} = 9 \). The cube root of this number is \( \sqrt[3]{9} \).
\sqrt[3]{9} = 3

(18) What is the square root of 0?

• (a) 0
• (b) 1
• (c) -1
• (d) Undefined

Answer

Correct Answer: (a) 0
The square root of 0 is \( \sqrt{0} = 0 \).
\sqrt{0} = 0

(19) What is the cube root of -64?

• (a) -2
• (b) -4
• (c) -6
• (d) -8

Answer

Correct Answer: (b) -4
The cube root of -64 is \( \sqrt[3]{-64} = -4 \).
\sqrt[3]{-64} = -4

(20) What is the square root of 121?

• (a) 11
• (b) 12
• (c) 13
• (d) 14

Answer

Correct Answer: (a) 11
The square root of 121 is \( \sqrt{121} = 11 \).
\sqrt{121} = 11