FREE Iowa Test of Basic Skills (ITBS) 8th Grade Questions and Answers

Question 1

Get the LCM of 224 and 280.

Accepted Answer

1120

Answer

To find the Least Common Multiple (LCM) of 224 and 280, first determine their prime factorizations: 224 = 2^5 × 7 and 280 = 2^3 × 5 × 7. The LCM is found by taking the highest power of all prime factors present in either number. Thus, LCM = 2^5 × 5^1 × 7^1 = 32 × 5 × 7 = 1120.

Question 2

A cube has a 725-cubic-centimeter volume. Which of the following comes closest to describing how long each cube edge is?

Accepted Answer

9 centimeters

Answer

The volume of a cube is calculated by cubing the length of one of its edges (V = s³). To find the edge length, you need to calculate the cube root of the volume. The cube root of 725 is approximately 8.98 centimeters. Among the given options, 9 centimeters is the closest whole number to this value.

Question 3

Which of the ensuing figures makes a perfect square?

Accepted Answer

25

Answer

A perfect square is an integer that can be expressed as the product of an integer multiplied by itself. Among the given options, 25 is a perfect square because it is the result of 5 multiplied by 5 (5 × 5 = 25). The other numbers are not products of an integer multiplied by itself.

Question 4

8 is reduced by adding a number, n, and the product of 5. Which expression best encapsulates this assertion?

Accepted Answer

8  (n + 5)

Answer

The phrase 'adding a number, n, and the product of 5' can be interpreted as 'adding n and 5,' which forms the sum (n + 5). The phrase '8 is reduced by' means that this sum is subtracted from 8. Therefore, the expression that best encapsulates this assertion is 8 - (n + 5).

Question 5

What is considered to be an error or alteration in an organism's DNA?

Accepted Answer

Mutation

Answer

A mutation is defined as a change or alteration in the DNA sequence of an organism. These changes can be small, like a single base pair change, or large, involving entire sections of chromosomes. Mutations are the fundamental source of genetic variation within a population.

ITBS - Iowa Test of Basic Skills Exam Practice Test

ITBS - Iowa Test of Basic Skills Exam Practice Test

FREE Iowa Test of Basic Skills (ITBS) 8th Grade Questions and Answers