Que porcentaje es 240 de 1420 y de 1680 de 8000

2/5 of the members of a school band are 6th graders. What percent of the students in the band are non-sixth graders?

A runner training for a marathon ran 18 miles in 150 minute. Find the length of time it takes the runner to cover 1 mile. Round to the nearest tenth.

You have two cats. Each cat has a litter of 6 kittens. Write an expression that describes the total number of cats and kittens you have.

Jessica made plans to weave a rectangular jute rug, but she needs to update the plans to change the dimensions of the rug. The original design has a length of 36 inches and a width of 60 inches.

If (2x+a) (2x+b) = 4x^2-4x+ab, then a+b = ? A. - 4 B. - 2 C. - 1 D. 2 E. 4