Square root and cube root

user November 19, 2023

(46) What is the square root of 400?

(a) 20
(b) 25
(c) 30
(d) 40

Correct Answer: (a) 20
The square root of 400 is $ \sqrt{400} = 20 $.
$\sqrt{400} = 20$

(47) If the cube root of a number is 7, what is the cube of that number?

(a) 14
(b) 343
(c) 686
(d) 1029

Correct Answer: (b) 343
If the cube root of a number is 7, then the number itself is $7^3 = 343$. The cube of this number is $343^3$.
$343^3 = 42,949,967$

(48) What is the smallest integer that when squared gives a number greater than 70,000?

(a) 260
(b) 270
(c) 271
(d) 280

Correct Answer: (c) 271
The smallest integer whose square is greater than 70,000 is 271 since $270^2 = 72,900$ and $271^2 = 73,441$.
$271^2 = 73,441 > 70,000$

(49) What is the cube root of 10000?

(a) 10
(b) 100
(c) 20
(d) 200

Correct Answer: (c) 20
The cube root of 10000 is $ \sqrt[3]{10000} = 20 $.
$\sqrt[3]{10000} = 20$

(50) If the square of a number is 225, what is the cube root of that number?

(a) 5
(b) 10
(c) 15
(d) 225

Correct Answer: (c) 15
If the square of a number is 225, then the number itself is $ \sqrt{225} = 15 $. The cube root of this number is $ \sqrt[3]{15} $.
$\sqrt[3]{15} = 3375$

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