Solve.Martha can rake the leaves in her yard in 4 hours. Her younger brother can do the job in 7 hours. How long will it take them to do the job if they work together?
A. 
hr
B. 2
hr
C. 7 hr
D. 9
hr
Answer: B
You might also like to view...
Write the numerator and denominator of the given fraction.
A. numerator: 5, denominator: 1
B. numerator: 
, denominator: 1
C. numerator: 6, denominator: 1
D. numerator: 1, denominator: 5
Solve the problem.The production function z for an industrial country was estimated as 
where x is the amount of labor and y the amount of capital. Find the marginal productivity of labor.
A. 7x6y5 B. 14x6y5 C. 10x7y4 D. 5x7y4
Solve the problem.The following scatter diagram shows heights (in inches) of children and their ages.Height (inches)
Age (years)Based on this data, how old do you think a child is who is about 39 inches tall?
A. 7 years B. 3 months C. 3 years D. 1 year
Tell which set or sets the number belongs to: natural numbers, whole numbers, integers, rational numbers, irrational numbers, and real numbers.- 
A. integer, real B. irrational, real C. whole, real D. rational, real