The number of children in the library was 3 times the number of adults. the total number of people at that library was 48. how many children were at the library?

The figure below shows rectangle abcd and the triangle eca on a coordinate plane. which of the following expressions represents the perimeter of triangle of triangle eca in units

He mass of a single atom of carbon can be found by dividing the atomic mass (12.01 g) by 6.022 x 10^23. which is the mass of a single carbon atom, correctly written in scientific notation with the correct number of significant figures?

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.