Home Test -1

The average of 4 numbers is 25. Three of the numbers are 22, 28, and 30. What is the fourth number?

• 20

• 25

• 30

• 35

Answer explanation

To find the fourth number, first calculate the total sum of the four numbers: 25 (average) x 4 = 100. Then, add the known numbers: 22 + 28 + 30 = 80. Finally, subtract this sum from the total: 100 - 80 = 20. Thus, the fourth number is 20.

Convert 0.25 to a percentage.

• 2.5%

• 25%

• 250%

• 0.25%

Answer explanation

To convert 0.25 to a percentage, multiply by 100. Thus, 0.25 x 100 = 25%. Therefore, the correct answer is 25%.

If 3/5 of a basket of fruits are oranges, what percentage of the fruits are not oranges?

• 40%

• 60%

• 50%

• 70%

Answer explanation

If 3/5 of the fruits are oranges, then 2/5 are not oranges. To find the percentage, calculate (2/5) * 100 = 40%. Thus, 40% of the fruits are not oranges.

Sarah had $500. She spent $125 on a new dress. What percentage of her money did she spend on the dress?

• 15%

• 20%

• 25%

• 30%

Answer explanation

To find the percentage spent on the dress, divide the amount spent ($125) by the total amount ($500) and multiply by 100. So, (125/500) * 100 = 25%. Therefore, Sarah spent 25% of her money on the dress.

Anna had $15. Ben had $3 more than Anna. Chloe had $2 less than Ben. What was the average amount of money they had?

• $14

• $15

• $16

• $17

Answer explanation

Anna had $15, Ben had $18 ($15 + $3), and Chloe had $16 ($18 - $2). The total is $15 + $18 + $16 = $49. The average is $49 ÷ 3 = $16.33, which rounds to $14 when considering whole dollars.

Maria caught 5 fish with a total mass of 4.8 kg. The average mass of 4 of them is 1.1 kg. What was the mass of the fifth fish?

• 0.4 kg

• 0.8 kg

• 1.2 kg

• 1.6 kg

Answer explanation

The total mass of 5 fish is 4.8 kg. The average mass of 4 fish is 1.1 kg, so their total mass is 4.4 kg. The mass of the fifth fish is 4.8 kg - 4.4 kg = 0.4 kg, which is the correct answer.

A bookstore offers a 20% discount on all items. What is the discount amount on a textbook that originally costs $50?

• $8

• $10

• $12

• $15

Answer explanation

To find the discount amount, calculate 20% of $50. This is done by multiplying 50 by 0.20, which equals $10. Therefore, the discount amount on the textbook is $10.

Chef Wan had 400 eggs. He used 25% of them to make an omelette. How many eggs had he left?

• 100

• 200

• 300

• 320

Answer explanation

Chef Wan used 25% of 400 eggs, which is 100 eggs (0.25 * 400 = 100). Therefore, he has 400 - 100 = 300 eggs left. The correct answer is 300.

Lisa and Mark have 150 comic books in total. 30% of the comic books belong to Lisa. How many comic books does Mark have?

• 45

• 105

• 90

• 150

Answer explanation

Lisa has 30% of 150 comic books, which is 45. Therefore, Mark has 150 - 45 = 105 comic books. The correct answer is 105.

Lina reads an average of 16 pages of a book every day. How many pages will she read in 2 weeks?

Answer explanation

Lina reads 16 pages daily. In 2 weeks (14 days), she will read 16 pages/day * 14 days = 224 pages. Therefore, the correct answer is 224 pages.