Percentages (Solving problems): แบบฝึกหัด

In a test with \(80\) questions, a student answers \(95\%\) of them correctly. How many questions did the student answer correctly?

A car's speed increases from \(60\text{ km/h}\) to \(75\text{ km/h}\). What is the percentage increase in speed?

A farm has \( 800 \) trees. \( 30\% \) are apple trees and \( 25\% \) are pear trees. Of the remaining trees, \( 40\% \) are peach trees and the rest are plum trees. How many plum trees are there on the farm?

A sports bag contains 50 items. If 15 of these items are footballs, what percentage of the total items in the bag are footballs?

A library has \( 500 \) books. In one year, \( 15\% \) of the books were damaged and removed. The library then bought new books equivalent to \( 25\% \) of the remaining books. How many books does the library have now?

A box of chocolates originally contains \(40\) pieces. If the manufacturer increases the number of pieces by \(25\%\), how many pieces of chocolate are there in the new box?

There are \( 200 \) staff members in a company. \( 45\% \) of them are male and the rest are female. If \( 30\% \) of the male staff and \( 20\% \) of the female staff commute to work by bus, how many staff members commute by bus in total?

In a school library, \( 40\% \) of the books are English books and the rest are Chinese books. Among the English books, \( 25\% \) are fiction stories. Among the Chinese books, only \( 15\% \) are fiction stories. If the library has a total of \( 57 \) fiction story books, how many books are there in the library altogether?

A gardener planted \( 120 \) seeds in a flowerbed. If \( 35\% \) of the seeds failed to sprout, how many seeds actually sprouted?

In a school library, there are \(25\) new books. \(8\) of them are storybooks, \(7\) of them are science books, and the rest are art books.