Percentage Calculations and Ratios

This video series covers seventh-grade illustrative mathematics, focusing on ratios, scaling, percentages, and measurement errors. Each lesson delves into specific mathematical concepts, providing examples and equations to enhance understanding.

If a rectangle has a height to width ratio of 3:4.5, which of the following could be a scaled version of this rectangle?

• 6:9

• 9:12

• 12:15

• 15:20

A cyclist rode 3.75 miles in 0.3 hours. What was her speed in miles per hour?

• 10 mph

• 17.5 mph

• 12.5 mph

• 15 mph

If a bakery used 25% more butter this month than last month, and last month they used 240 kg, how much butter did they use this month?

• 300 kg

• 260 kg

• 320 kg

• 280 kg

A pair of sneakers was bought for $120 and its price increased by 15%. What is the new price?

• $138

• $135

• $130

• $140

In a video game, Claire scored 50% more points than Tyler. If Tyler scored 100 points, how many points did Claire score?

• 150 points

• 125 points

• 200 points

• 100 points

If a bakery used 560 kg of sugar last month and 30% more this month, how much sugar did they use this month?

• 580 kg

• 700 kg

• 728 kg

• 600 kg

What is the sales tax rate in Nevada if a $10 item has a sales tax of $0.46?

• 5.5%

• 4.6%

• 5.0%

• 4.0%

A store marks up a guitar by 30% and sells it for $58.50. What was the original price?

• $50.00

• $55.00

• $45.00

• $40.00

If a thermometer reads 331.5°F but the actual temperature is 325°F, what is the percentage error?

• 1.5%

• 2%

• 1%

• 2.5%

A student estimated a task would take 3 hours, but it took 5 hours. What is the percent error?

• 40%

• 50%

• 60%

• 30%