Does a trapezoid have exactly one pair of parallel sides always?

In trapezoid klmn, kj=19.2 and jm=22.5. identify ln.

Analyze the data sets below. data set a 25,25,25,26,26,26,27,28,28,29,30,31,31,32,33,33,34,35,35,35 data set b 25,25,25,26,26,26,26,27,27,27,27,28,28,29,29,30,31,31,32,34 which of the following statement are true? select all that apply. a. data set a is relatively symmetric and data set b is skewed left. b.the means of the data sets are within 3 units from eachother. c.the data sets have the same standard deviation. d.the mean of data set a is 27.95 and the mean of data set b is 30. e. the data set b has a higher standard deviation than data set a. f. the mean and median of data set a are close in value.

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?