UNESCO LS3

Which of the following do not belong to the group of numbers?

• Two

• four

• three

• six

Answer explanation

• Two: This is an even number.

• Four: This is also an even number.

• Three: This is an odd number.

• Six: This is an even number

Which of the following is a set of even integers?

• { 2, 4, 6, 7 }

• 
  { 1, 3, 5, 7 }

• 
  { 2, 4, 6, 8 }

• { 1, 2, 3, 4 }

Answer explanation

The set { 2, 4, 6, 8 } contains only even integers, as they are all divisible by 2. The other sets include odd integers or a mix of odd and even, making { 2, 4, 6, 8 } the only correct choice.

Let B = { 6, 9, 12 } and C = { 6, 12, 18 }. What is B ∪ C?

• { 6, 9, 12, 15 }

• 
  { 6, 9, 12, 18 }

• { 6, 9, 15, 18 }

• { 3, 9, 12, 18 }

Answer explanation

The union of sets B and C combines all unique elements from both sets. B = {6, 9, 12} and C = {6, 12, 18}. Thus, B ∪ C = {6, 9, 12, 18}, making the correct answer {6, 9, 12, 18}.

Let X = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 } and Y = { 2, 4, 6, 8 }. What is X ∩ Y?

• 
  ∅

• 
  { 1, 3, 4, 5, 7 }

• { 2, 4, 6, 8 }

• { 0, 1, 3, 9 }

Answer explanation

The intersection X ∩ Y includes elements common to both sets. Here, Y = {2, 4, 6, 8} consists of even numbers, all of which are present in X. Therefore, X ∩ Y = {2, 4, 6, 8} is the correct answer.

In a number line, what are the integers on the left of 0?

• Decimals

• Positive integers

• Fractions

• Negative integers

Answer explanation

On a number line, integers to the left of 0 are negative integers. They are less than zero, while positive integers are to the right of 0. Decimals and fractions are not integers.

If A = 2, what is the integer 4 units to the right of A?

• 2

• 4

• 6

• 8

Answer explanation

To find the integer 4 units to the right of A (which is 2), you add 4 to A: 2 + 4 = 6. Therefore, the correct answer is 6.

Which of the following expression represents “x is greater than −3”?

• x > −3

• x ≥ −3

• 
  x < −3

• x ≤ −3

Answer explanation

The expression "x > -3" correctly represents that x is greater than -3.

John had 4 mangoes. He bought 3 more at the market. How many mangoes does he have in all?

• 7

• 9

• 8

• 10

Answer explanation

John initially had 4 mangoes and bought 3 more. To find the total, add 4 + 3, which equals 7. Therefore, the correct answer is 7.

Avery is studying polynomials in her math class. She comes across the following expressions and wonders which one is a binomial.

• 4x^3

• 
  x^3 + x − 2

• 2x^2 + x

• 3x^2 + x + 1

Answer explanation

A binomial is a polynomial with exactly two terms. The expression 2x^2 + x has two terms, making it a binomial. The other options have more than two terms, thus they are not binomials.

Grace is studying polynomials in her math class. She learns that the highest sum of the exponents of the variables in a polynomial is an important concept. What do you call this highest sum?

• variable

• degree

• term

• exponent

Answer explanation

The highest sum of the exponents of the variables in a polynomial is called the 'degree'. This term is used to describe the polynomial's overall complexity based on its variable powers.