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easy maths question

Easy maths question that I cant do hahaha

Jessica takes twice as long as Tiffany to finish a task. Together, they finish the task in 6 hours. How much time will Jessica take if she works alone?
(edited 7 years ago)
Original post by mathematigeek
J + T = 6
J = 2*T

By substitution, 3*T = 6, so Tiffany takes 2 hours alone and Jessica takes 4 hours.

(I think?)


if it takes them 6 hours to finish it by working together, how can jessica finish it in a shorter time by working on her own?

surely if they both finish it together in 6 hours, and jessica works twice as slow as tiffany, then she does a third of the total work in 6 hours, meaning she does all the work on her own in 18 hours?
(edited 7 years ago)
Original post by KloppOClock
if it takes them 6 hours to finish it by working together, how can jessica finish it in a shorter time by working on her own?

surely if they both finish it together in 6 hours, and jessica works twice as slow as tiffany, then she does a third of the total work in 6 hours, meaning she does all the work on her own in 18 hours?


Yes, I agree. The question was ambiguously worded, hence my uncertainty. Thank you!
I think it would be that it takes Jessica 8 hours on her own.

I agree with what @mathematigeek said. so take J = 4 hours and T = 2 hours. So think of it like this Jessica needs to do what Tiffany takes 2 hours to do so 2*2=4 (as she takes twice as long) plus the 4 hours she takes to do her own part and you have 8 hours.
Original post by KappaRoss
I think it would be that it takes Jessica 8 hours on her own.

I agree with what @mathematigeek said. so take J = 4 hours and T = 2 hours. So think of it like this Jessica needs to do what Tiffany takes 2 hours to do so 2*2=4 (as she takes twice as long) plus the 4 hours she takes to do her own part and you have 8 hours.


your assuming that they do equal amounts of work, they work together for 6 hours and tiffany works twice as fast then she does 2 thirds of the total work in 6 hours, meaning that jess does a third of the work in 6 hours, then times by 3
Posted from TSR Mobile

I guess the question can be seen in many ways.
Taking twice as long doesn't mean you necessarily do less work. They could do equal amounts of work and still take different amounts of time.
Original post by KappaRoss
Posted from TSR Mobile

I guess the question can be seen in many ways.
Taking twice as long doesn't mean you necessarily do less work. They could do equal amounts of work and still take different amounts of time.


It is quite an ambiguous question! Maybe it has been paraphrased? I'm sure if the OP has the answer/could ask a tutor, one of the provided workings would help them :smile:
Original post by KappaRoss
Posted from TSR Mobile

I guess the question can be seen in many ways.
Taking twice as long doesn't mean you necessarily do less work. They could do equal amounts of work and still take different amounts of time.


" Jessica takes twice as long as Tiffany to finish a task. "
If someone takes longer to do something, it means they work at a slower rate. if you have two people who are simultaneously working at the same time, then overall, the person who works faster will have done more work. I don't think the question can been seen in many ways.
Reply 8
Thanks guys for trying to help! The answer is 18 hours!

(1/2T + 1/T) * 6 = 1 task completeted
9 = T

If Tiffany works alone, she would have taken 9 hours. Since Jessica will take twice as long, it would be 9 * 2 and the final answer is 18. 😊

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