Solve the problem. See Example.EXAMPLE Dividing a Board into PiecesA project calls for thr...

Solve the problem. See Example.

EXAMPLE Dividing a Board into Pieces

A project calls for three pieces of wood. The longest piece must be twice the length of the middle-sized piece. The shortest piece must be 10 in. shorter than the middle­sized piece. If a board 70 in. long is to be used, how long can each piece be?

Step 1 Read the problem. There will be three answers.

Step 2 Assign a variable. Since the middle-sized piece appears in both pairs of comparisons, let x represent the length, in inches, of the middle-sized piece.

A sketch is helpful here. See FIGURE 2.

FIGURE 2

Step 3 Write an equation.

Step 4 Solve.

Step 5 State the answer. The middle-sized piece is 20 in. long, the longest piece is 2(20) = 40 in. long, and the shortest piece is 20 − 10 = 10 in. long.

Step 6 Check. The lengths sum to 70 in. All problem conditions are satisfied.

A mathematics textbook editor spent 7.5 hr making telephone calls, writing e-mails, and attending meetings. She spent twice as much time attending meetings as making telephone calls and 0.5 hr longer writing e-mails than making telephone calls. How many hours did she spend on each task?