1.
What is 25% of 80?
Correct Answer
A. 20
Explanation
Percentages are a way of representing a part of a whole as a fraction of one hundred. The symbol '%' denotes a percentage. In this case, 25% means 25 out of every hundred. To find 25% of 80, we first need to convert the percentage into a decimal. We do this by dividing 25 by 100, which gives us 0.25. Then, we multiply this decimal by the whole amount, 80. So, 0.25 multiplied by 80 equals 20. Therefore, 25% of 80 is 20.
2.
If a train travels 300km in 5 hours, what is its average speed?
Correct Answer
C. 60 km/h
Explanation
Speed is a measure of how quickly an object moves over a certain distance. To calculate the average speed, we divide the total distance traveled by the total time taken. In this scenario, the train travels 300 kilometers in 5 hours. Therefore, to find the average speed, we divide 300 km by 5 hours, which gives us 60 kilometers per hour.
3.
A shirt costs $20 after a 20% discount. What was the original price?
Correct Answer
C. $25
Explanation
When a discount is applied to an item, its price is reduced by a certain percentage. In this case, the shirt has a 20% discount, which means the final price of $20 represents 80% of the original price (100% - 20% = 80%). To find the original price, we need to figure out what number $20 is 80% of. We can do this by dividing the final price ($20) by the decimal equivalent of the remaining percentage (80% = 0.8). So, $20 divided by 0.8 equals $25, which was the original price of the shirt.
4.
What is the next number in the sequence: 2, 4, 6, 8, __?
Correct Answer
C. 10
Explanation
This is an example of an arithmetic sequence, where each number is increased by a constant value to get the next number. In this sequence, the constant value, or common difference, is 2. To find the next number in the sequence, we simply add the common difference of 2 to the last number, 8. Therefore, the next number in the sequence is 8 + 2 = 10.
5.
If a recipe requires 2 cups of flour for 12 cookies, how many cups are needed for 36 cookies?
Correct Answer
B. 6 cups
Explanation
This question requires us to understand the concept of proportionality. If 2 cups of flour are needed to make 12 cookies, we can use this ratio to find out how much flour is needed for any number of cookies. Since we want to make 36 cookies, which is three times the original amount (36 / 12 = 3), we also need three times the amount of flour. Therefore, we multiply the original amount of flour (2 cups) by 3, which gives us 6 cups of flour.
6.
A rectangle has a length of 10cm and a width of 5cm. What is its area?
Correct Answer
C. 50cm²
Explanation
The area of a shape is the amount of space it occupies within its boundaries. For a rectangle, the area is calculated by multiplying its length by its width. In this case, the rectangle has a length of 10 centimeters and a width of 5 centimeters. So, to find the area, we multiply 10 cm by 5 cm, which equals 50 square centimeters (cm²).
7.
If a car uses 10 liters of fuel to travel 100km, how many liters will it use for 250km?
Correct Answer
C. 25 liters
Explanation
This problem involves understanding the relationship between fuel consumption and distance traveled. If a car uses 10 liters of fuel to travel 100 kilometers, we can use this information to calculate the fuel needed for any distance. Since the car needs to travel 250 kilometers, which is 2.5 times the original distance (250 / 100 = 2.5), it will also need 2.5 times the amount of fuel. Therefore, we multiply the original fuel consumption (10 liters) by 2.5, which gives us 25 liters.
8.
What is the value of 3 + 6 x 2?
Correct Answer
A. 15
Explanation
In mathematics, the order of operations is a set of rules that dictate the sequence in which calculations are performed. A common mnemonic to remember this order is PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction) or BODMAS (Brackets, Orders, Division and Multiplication, Addition and Subtraction). Following these rules, we perform multiplication before addition. Therefore, we first calculate 6 multiplied by 2, which equals 12. Then, we add 3 to 12, which gives us 15.
9.
A shop sells apples for $1.50 each. How much will 5 apples cost?
Correct Answer
C. $7.50
Explanation
To calculate the total cost of multiple items with the same price, we multiply the price per item by the number of items. In this case, each apple costs $1.50, and we want to buy 5 apples. So, we multiply $1.50 by 5, which equals $7.50.
10.
What is 15% of 200?
Correct Answer
C. 30
Explanation
Similar to the first question, we need to convert the percentage to a decimal before performing the calculation. 15% is equivalent to 15 divided by 100, which is 0.15. To find 15% of 200, we multiply the decimal equivalent of the percentage (0.15) by the whole amount (200). So, 0.15 multiplied by 200 equals 30. Therefore, 15% of 200 is 30.