The large square above has sides of length 1. It is divided into smaller squares by dividing each side into 10 equal parts. In the figure, 3 full rows and 4 smaller squares in the next row are shaded. What is the area of the shaded region?
- A. 0.34
- B. 0.37
- C. 0.43
- D. 0.7
Correct Answer & Rationale
Correct Answer: A
To determine the area of the shaded region, first note that the large square has a side length of 1, resulting in a total area of 1 square unit. Each side is divided into 10 equal parts, creating a grid of 100 smaller squares, each with an area of 0.01 (1/100). In the figure, 3 full rows of squares are shaded, which accounts for 30 squares (3 rows x 10 squares per row). Additionally, 4 squares are shaded in the fourth row, bringing the total shaded squares to 34. Thus, the area of the shaded region is 34 squares x 0.01 = 0.34. Option B (0.37) incorrectly suggests 37 squares shaded. Option C (0.43) implies 43 squares, which is not possible given the shading described. Option D (0.7) overestimates the shaded area, miscounting the total squares shaded.
To determine the area of the shaded region, first note that the large square has a side length of 1, resulting in a total area of 1 square unit. Each side is divided into 10 equal parts, creating a grid of 100 smaller squares, each with an area of 0.01 (1/100). In the figure, 3 full rows of squares are shaded, which accounts for 30 squares (3 rows x 10 squares per row). Additionally, 4 squares are shaded in the fourth row, bringing the total shaded squares to 34. Thus, the area of the shaded region is 34 squares x 0.01 = 0.34. Option B (0.37) incorrectly suggests 37 squares shaded. Option C (0.43) implies 43 squares, which is not possible given the shading described. Option D (0.7) overestimates the shaded area, miscounting the total squares shaded.
Other Related Questions
Kayla has a stack of photographs that is 20 centimeters high. If each photograph is 0.04 cm thick, how many photos are there in the stack?
- A. 8
- B. 50
- C. 80
- D. 500
Correct Answer & Rationale
Correct Answer: D
To determine the number of photographs in the stack, divide the total height of the stack by the thickness of each photograph. The stack is 20 cm high and each photograph is 0.04 cm thick. Calculating this gives: 20 cm ÷ 0.04 cm = 500 photographs. Option A (8) is incorrect as it underestimates the total by not accounting for the thickness appropriately. Option B (50) also miscalculates the total, suggesting a much smaller number of photographs. Option C (80) is an overestimation, failing to consider the correct division of height by thickness. Only option D (500) accurately reflects the calculation, confirming the total number of photographs in the stack.
To determine the number of photographs in the stack, divide the total height of the stack by the thickness of each photograph. The stack is 20 cm high and each photograph is 0.04 cm thick. Calculating this gives: 20 cm ÷ 0.04 cm = 500 photographs. Option A (8) is incorrect as it underestimates the total by not accounting for the thickness appropriately. Option B (50) also miscalculates the total, suggesting a much smaller number of photographs. Option C (80) is an overestimation, failing to consider the correct division of height by thickness. Only option D (500) accurately reflects the calculation, confirming the total number of photographs in the stack.
165 is what percent of 150?
- A. 95%
- B. 110%
- C. 111%
- D. 115%
Correct Answer & Rationale
Correct Answer: B
To find what percent 165 is of 150, divide 165 by 150 and then multiply by 100. This calculation yields 110%, indicating that 165 is 110% of 150. Option A (95%) is incorrect as it underestimates the relationship between the two numbers. Option C (111%) slightly overestimates the value, while Option D (115%) significantly exaggerates it. Each of these options fails to accurately represent the proportion of 165 to 150, reinforcing that 110% is the precise measure of this relationship.
To find what percent 165 is of 150, divide 165 by 150 and then multiply by 100. This calculation yields 110%, indicating that 165 is 110% of 150. Option A (95%) is incorrect as it underestimates the relationship between the two numbers. Option C (111%) slightly overestimates the value, while Option D (115%) significantly exaggerates it. Each of these options fails to accurately represent the proportion of 165 to 150, reinforcing that 110% is the precise measure of this relationship.
What is 0.3 percent of 90?
- A. 0.027
- B. 0.27
- C. 0.3
- D. 2.7
Correct Answer & Rationale
Correct Answer: B
To find 0.3 percent of 90, convert the percentage to a decimal by dividing by 100, resulting in 0.003. Then, multiply 0.003 by 90, yielding 0.27. Option A (0.027) is too small, as it miscalculates the multiplication. Option C (0.3) represents the percentage itself, not the calculated value of 0.3 percent of 90. Option D (2.7) is ten times larger than the correct answer, indicating a misunderstanding of the percent calculation. Thus, B (0.27) accurately represents 0.3 percent of 90.
To find 0.3 percent of 90, convert the percentage to a decimal by dividing by 100, resulting in 0.003. Then, multiply 0.003 by 90, yielding 0.27. Option A (0.027) is too small, as it miscalculates the multiplication. Option C (0.3) represents the percentage itself, not the calculated value of 0.3 percent of 90. Option D (2.7) is ten times larger than the correct answer, indicating a misunderstanding of the percent calculation. Thus, B (0.27) accurately represents 0.3 percent of 90.
Which of the four labeled points on the number line above has coordinate-?
- A. A
- B. B
- C. C
- D. D
Correct Answer & Rationale
Correct Answer: B
Point B is positioned at the coordinate -2 on the number line, making it the accurate choice. Point A is located at -1, which is not the specified coordinate. Point C is at 0, representing the origin, and thus does not match the target coordinate. Point D is found at 1, clearly outside the negative range required. Each of these points is distinctly marked, confirming that only Point B aligns with the coordinate of -2. This clarity in placement reinforces the understanding of negative values on a number line.
Point B is positioned at the coordinate -2 on the number line, making it the accurate choice. Point A is located at -1, which is not the specified coordinate. Point C is at 0, representing the origin, and thus does not match the target coordinate. Point D is found at 1, clearly outside the negative range required. Each of these points is distinctly marked, confirming that only Point B aligns with the coordinate of -2. This clarity in placement reinforces the understanding of negative values on a number line.