A jar contains 10 red marbles and 30 green marbles . How many red marbles must be added to the jar so that 60% of the marbles will be red ?
Karim drove for h hours at a constant rate of r miles per hour . How many miles did he go during the final 20 minutes of his drive ?
What is the are a of a square (in sq. meter) if its perimeter is 40 meter ?
1 + 2 + 3 + .................. + 100 = ?
From 2004 to 2005. the sales of a book decreased by 80%. If the sales in 2006 were the same as in 2004, by what percent did they increase from 2005 to 2006 ?
The average of 10 numbers is ---10. If the sum of 6 of them is 100, then what is the average of the other 4 numbers ?
If x% of y is 10, then what is y ?
If the product of 4 consecutive integers is equal to one of them , then what is the largest possible value of one of the integers ?
In a class , the ratio of the number of boys to girls is 5 : 3 . What percent of the students of the class are girls ?
Karim has exactly 3 times as many Bangladesh as non-Bangladesh stamps in his collection . Which of the following cannot be the number of stamps in Karim's collection ?