找到你今天要练的题。

The regular price of a shirt at a store is $11.70. The sale price of the shirt is 80% less than the regular price, and the sale price is 30% greater than the store's cost for the shirt. What was the store’s cost, in dollars, for the shirt? (Disregard the $ sign when entering your answer. For example, if your answer is $4.97, enter 4.97)

The value of an autographed baseball increased by 173% from the end of 2013 to the end of 2014 and then decreased by 18% from the end of 2014 to the end of 2015. What was the net percentage increase in the value of the autographed baseball from the end of 2013 to the end of 2015?

A clothing store buys shirts at a wholesale price of 4.00 dollars each and resells them each at a retail price that is 280% of the wholesale price. At the end of the season, any remaining shirts are marked at a discounted price that is 80% off the retail price. What is the discounted price of each remaining shirt, in dollars?

A gift shop buys souvenirs at a wholesale price of 7.00 dollars each and resells them each at a retail price that is 290% of the wholesale price. At the end of the season, any remaining souvenirs are marked at a discounted price that is 80% off the retail price. What is the discounted price of each remaining souvenir, in dollars?

A researcher investigated two species of mites: a predator and its prey. At the start of a week, there was an equal number of the two species. At the end of the week, the number of prey had increased by 2100% of the number of prey at the start of the week, and the number of predators had increased by 450% of the number of predators at the start of the week. The number of predators at the end of the week was p% less than the number of prey at the end of the week. What is the value of p?

A researcher investigated two species of mites: a predator and its prey. At the start of a week, there was an equal number of the two species. At the end of the week, the number of prey had increased by 2,700% of the number of prey at the start of the week, and the number of predators had increased by 180% of the number of predators at the start of the week. The number of prey at the end of the week was p% greater than the number of predators at the end of the week. What is the value of p?

The price of an item increased by p% from $18 to $21. What is the value of p?

In 2013, Chloe earned 11% more than in 2012, and in 2014 Chloe earned 6% more than in 2013. If Chloe earned y times as much in 2012 as in 2014, which of the following is closest to the value of y?

In 2007, Elijah earned 17% more than in 2006, and in 2008 Elijah earned 3% more than in 2007. If Elijah earned y times as much in 2006 as in 2008, which of the following is closest to the value of y?  

The population of City A increased by 9% from 2015 to 2016.If the 2016 population is k times the 2015 population, what is the value of k?

A scientist studying the life cycle of butterflies counted the number of butterflies in a certain habitat each day for 46 days. On June 15, there were 152 butterflies in the habitat. The percent increase in the number of butterflies in the habitat from May 1 to June 15 was 18.75%. How many butterflies were in the habitat on May 1?

A scientist studying the life cycle of butterflies counted the number of butterflies in a certain habitat each day for 46 days. On June 15, there were 126 butterflies in the habitat. The percent increase in the number of butterflies in the habitat from May 1 to June 15 was 31.25%. How many butterflies were in the habitat on May 1?