If they work together, they need 15/8 hours to assemble one shelving unit.
What does work mean in math?
According to tittle, we know worker A can  assemble a shelving unit in 5 hours , which means worker A can finish 1/5 of work in 1 hour . And worker B can finish 1/3 of work in 1 hour.
If A & B work together , they will spend the same time t to assemble only one shelving .
That means, Â Â Â Â Â Â Â Â Â 1/5t + 1/3 t = 1 Â Â Â Â Â Â Â Â Â Â Â Â (equation)
1/5 t is worker A's workload during time t , 1/3 t is worker B workload.
So, Â 1/5 t + 1/3t = 1 Â is the answer
   ⇒ 5t + 3t = 15
   ⇒ t = 15/8 hours
If they work together, they need 15/8 hours to assemble one shelving unit.
Learn more about work
brainly.com/question/6945126
#SPJ4
   Â