1.
What is the sum of 45 and 55?
Correct Answer
B. 100
Explanation
The sum of 45 and 55 is calculated by directly adding the two numbers together. When you add 45 to 55, the total reaches 100. This is an addition problem involving two integers, which results in a straightforward calculation: 45 + 55 = 100. This demonstrates the basic principle of addition where the values are combined to form a single total, which in this case is a round hundred.
2.
How many sides does a pentagon have?
Correct Answer
B. 5
Explanation
A pentagon is defined as a polygon with five sides. This geometric fact categorizes it among other polygons like squares (four sides) and hexagons (six sides). Recognizing the number of sides from the name is key, as "penta" suggests five, thereby confirming that the correct number of sides for a pentagon is five.
3.
What is the product of 8 and 12?
Correct Answer
B. 96
Explanation
The product of 8 and 12 involves multiplication, a basic arithmetic operation. Calculating 8 x 12 gives 96. This multiplication is straightforward, using single-digit numbers to produce a double-digit result, emphasizing the scalability of multiplication over addition in generating larger numbers more efficiently.
4.
What is 15% of 200?
Correct Answer
C. 30
Explanation
Finding 15% of 200 involves a basic percentage calculation. Percentages are fractions of 100; thus, 15% means 15 per 100. The calculation is 200 x 0.15 = 30. This reflects understanding of percentage as a proportional measure relative to a base of 100, useful for comparing quantities in different scales.
5.
How many degrees are in a right angle?
Correct Answer
B. 90
Explanation
The number of degrees in a right angle is always 90. This is a fundamental property of Euclidean geometry, where a right angle defines the intersection of two lines that create a 90-degree angle, a quarter of a full rotation (360 degrees). Recognizing this helps in understanding angular measurements and their applications.
6.
What is the square root of 144?
Correct Answer
B. 12
Explanation
The square root of 144 is determined by finding a number which when multiplied by itself yields 144. This number is 12, since 12 x 12 = 144. Square roots are fundamental in geometry and algebra, particularly in solving equations and understanding areas of squares.
7.
What is the result of subtracting 50 from 125?
Correct Answer
C. 75
Explanation
Subtracting 50 from 125 is a simple subtraction operation: 125 - 50 = 75. This calculation deals with reducing a quantity by another, showing how quantities decrease and teaching basic subtraction, a critical arithmetic skill for balancing or comparing quantities.
8.
What is the area of a rectangle with sides 10 and 5?
Correct Answer
C. 50
Explanation
To find the area of a rectangle with sides 10 and 5, multiply the length by the width: 10 x 5 = 50. This represents a core principle in geometry where area is calculated as the product of length and width, reflecting the two-dimensional space a shape covers.
9.
How many edges does a cube have?
Correct Answer
C. 12
Explanation
A cube has 12 edges. This is a geometric property of cubes, which are three-dimensional figures with equal-length sides. Each of the six faces of a cube is a square, and each square face contributes four edges, but since each edge is shared by two faces, the total is twelve.
10.
What is 20 divided by 4?
Correct Answer
B. 5
Explanation
Dividing 20 by 4 results in 5. This operation is basic division, where 20 is divided equally into four parts. Division is the inverse of multiplication and is fundamental in distributing a total into equal parts, a useful skill in fractions, ratios, and proportional reasoning.