Find the circumference of 21cm

On their way home from school. terri and evie started walking out for two blocks and then running for three blocks and then repeating that pattern. if they can walk a block in 2 minutes and run a block and 45 seconds how long will it take them to go 18 blocks?

The length of a rectangle plus its width is 25 cm. the area is 156 square cm. what are the length and width of the rectangle? separate the answers with a comma.

Afamily has five members. a mom, a dad, two sisters, & a brother. the family lines up single file. what is the probabillity that the mom is at the front of the line