the question is :Two cranes can unload a ship together in 15 hours. The faster crane takes 16 hours less than the slower crane, if each were to unload the same ship alone. How long doesi t take for each crane to unload this ship? I done most of the math but i am stuck with this last part .15+- radical 1185/2
No. of hours for the slower to unload alone—x: 1/x + 1/(x - 16) = 1/15 (x - 16 + x)/(x? - 16x) = 1/15 15(2x - 16) = x? - 16x 30x - 240 = x? - 16x x? - 46x = - 240 x? - 23x = - 240 + (- 23)? x? - 23x = - 240 + 529 (x - 23)? = 289 x - 23 = 17 x = 40 No. of hours for the faster to unload alone: = 40 - 16 = 24 Answer: slower crane, 40 hrs; faster crane, 24 hrs Check: = 15(1/40 + 1/24) = 15([3 + 5]/120) = 15(8/120) = 15(1/15) = 15/15 or 1
