Pane can make a handcrafted drum in 4 weeks. Zane can make a similar handcrafted drum in 6 weeks. If they both work together, how many weeks will it take for them to produce 15 handcrafted drums? Choose the correct answer.
A) 30 B) 36 C) 70 D) 80 E) 150
Method I: the rates solution   “Pane can make a handcrafted drum in 4 weeks. Zane can make a similar handcrafted drum in 6 weeks.” Pane’s rate is (1 drum)/(4 weeks) = 1/4. Zane’s rate is (1 drum)/(6 weeks) = 1/6. The combined rate of Pane + Zane is   R = 1/4 + 1/6 = 3/12 + 2/12 = 5/12   That’s the combined rate. We need to make 15 drums — we have a rate and we have an amount, so use the “art” equation to solve for time:   T = A/R = 15/(5/12) = 15*(12/5) = (15/5)*12 = 3*12= 
<gadget id="calculator">3*12</gadget>
<output>36</output>
36   BTW, notice in the penultimate step, the universal fraction strategy: cancelbeforeyou multiply (Tip #3:http://magoosh.com/gmat/2012/can-i-use- ... -the-gmat/. Mane and Zane need 36 weeks to make 15 drums.   Answer= 36.
<result>B</result>
Pane can make a handcrafted drum in 4 weeks. Zane can make a similar handcrafted drum in 6 weeks. If they both work together, how many weeks will it take for them to produce 15 handcrafted drums?