another tricky question
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another tricky question
Hi
Can anyone help with these qeustions:
TV 1 and TV 2 are televisions channels both showing films that start at 8:30 pm.
TV 1 puts on advertisements every 10 minutes after the start of a film.
TV 2 puts on advertisements every 15 minutes after the start of a film.
Q. What is the is earliest time that there will be advertisements on both channels at the same time?
answer 9:00pm
Q. If the shortest film ends after 2 hours, how many times (during the films) will advertisements appear on both channels at the same time?
answer 3
Can anyone help with these qeustions:
TV 1 and TV 2 are televisions channels both showing films that start at 8:30 pm.
TV 1 puts on advertisements every 10 minutes after the start of a film.
TV 2 puts on advertisements every 15 minutes after the start of a film.
Q. What is the is earliest time that there will be advertisements on both channels at the same time?
answer 9:00pm
Q. If the shortest film ends after 2 hours, how many times (during the films) will advertisements appear on both channels at the same time?
answer 3
Re: another tricky question
I always find a diagram helps !
Re: another tricky question
You need to think of common factors or 10 & 15.
So, they will meet 30mins after the program starts for the first time and in 2hrs period they will cross each other 3 times. 9.00pm, 9.30pm, 10.00pm
I hope I am correct.
So, they will meet 30mins after the program starts for the first time and in 2hrs period they will cross each other 3 times. 9.00pm, 9.30pm, 10.00pm
I hope I am correct.
Re: another tricky question
Common multiples, not common factors. The common factor is 5. The common multiples are 30, 60, 90 which are what is wanted here.svg123 wrote:You need to think of common factors of 10 & 15.
Re: another tricky question
still think a diagram would help...
Re: another tricky question
Sorry, yes common multiple.xyzzy wrote:Common multiples, not common factors. The common factor is 5. The common multiples are 30, 60, 90 which are what is wanted here.svg123 wrote:You need to think of common factors of 10 & 15.
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Re: another tricky question
How about a diagram?
Re: another tricky question
Well, maybe a number line with times on it? I guess that's a kind of diagram. But having said that it's a pretty easy one to do without writing anything down and in an exam it would be quicker not to.
What was tricky about it?
What was tricky about it?
Re: another tricky question
Thanks everyone for helping.
Re: another tricky question
I think this is a silly question as it doesn't allow for the adverts to actually take up any time! Surely if the adverts were on every 10 or 15 minutes, you'd need to allow for 2-3 minutes each advert break (unless it's Sky-then about 6!) which would mess the times up