tricky maths question? help please!

" In a factory, Machine A is three times as quick as Machine B in assembling identical circuit boards. Machine A is allocated two and a half times as many of these circuit boards to assemble as Machine B. Machine B took 4 hours to assemble all of its allocation. How long did it take for Machine A to complete its allocation? Give your answer in hours and minutes. "

The mark scheme was quite confusing on how it got to the answer and I was wondering if anyone knew how to explain it??


Thank you in advance xo

This is what I got...

TIME A = TIME B / 3 (because machine A is 3 times as fast)

If TIME B = 240 mins (4 hours to complete allocation) , TIME A = 240 mins / 3 = 80 mins (to complete the same amount)

But, machine A had 2.5 times more to complete so...

2.5 * 80 mins = 200 mins = 3 hours and 20 mins.

Hope this helps

Wow, lovely! Thank you so much!!!

" In a factory, Machine A is three times as quick as Machine B in assembling identical circuit boards. Machine A is allocated two and a half times as many of these circuit boards to assemble as Machine B. Machine B took 4 hours to assemble all of its allocation. How long did it take for Machine A to complete its allocation? Give your answer in hours and minutes. "