Time to get a new clock?

[devadiva]

A clock was correct at midnight then it began to lose 3.5 minutes per hour - it ran for less than 24 hours. It stopped 2 hours ago showing 16.57 - what time is it now?

[daisya]

I think the answer is in your title.....<smile>

[factor-fiction]

*It stopped 2 hours ago showing 16.57 - what time is it now?
It puzzles me as to why that bit has been added. Doesit mean 2 hours ago according to a clock that shows the correct time or 2 hours according to a faulty clock?

[factor-fiction]

8pm

[jomifl]

How much less than 24 hours?

[factor-fiction]

The clock had stopped after it had run for 16 hours and 57 minutes as recorded on the faulty clock. That translates to (16 x 60) +57= 1017 minutes according to the faulty clock.
The faulty clock recorded 56.5 minutes for every 60 minutes in normal time. So the 1017 minutes on this clock is actually 1017 x 60/56.5=1080 minutes on a normal clock.
1080 minutes = 18 hours. So the clock stopped at 6pm in real time. That was 2 hours ago so it's now 8pm

[devadiva]

Goodness me - what a way to start the week- I thought it might be simple, the clock having stopped two hours ago at 16.57, losing 3.5 minutes per hour would make it now 16.50-does anyone agree? ANSWERS ON A POSTCARD PLEASE!

[bibblebub]

factor30 is right. let me try to put it slightly differently:-

it is now 16:57 which means that it has been running for 1017 minutes since midnight when it was correct

it loses 3.5 minutes per hour so that for every hour in real time it will only progress by 56.5 minutes

therefore for it to have progressed by 1017 minutes will take 1017/56.5 =18 hours

but it stopped 2 hours hour ago so that it is now 18+2 hours after midnight i.e. 8pm