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Re: If a phone call costs a cents for the first minute and a/3 cents
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17 Dec 2014, 05:42

Could someone please help with this question? I thought "a b-minute" could also be half-a-minute in which case it costs a/2 cents. IOW, the cost of "b" minutes is ab, no?

If a phone call costs a cents for the first minute and a/3 cents
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17 Dec 2014, 05:55

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Blackbox wrote:

If a phone call costs a cents for the first minute and a/3 cents for each additional half-minute, how much a b minute phone call cost, in cents ?

Could someone please help with this question? I thought "a b-minute" could also be half-a-minute in which case it costs a/2 cents. IOW, the cost of "b" minutes is ab, no?

A call less than or equal to 1 minute costs a cents. So, if b = 1/2 minutes the cost would still be a cents.

Easy way would be to just plug numbers, say a = 1 cent and b = 1 minute what would be the cost of a call then? It would cost 1 cent. Plug a = b = 1 and check for an option which would give 1. Only B fits.
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Re: If a phone call costs a cents for the first minute and a/3 cents
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05 Jan 2015, 07:19

This is what I though after reading this:

First minute: a --> this actually means "a" times the number of minutes; in this case a*1. Extra minutes: (2a)/3 --> a/3 for half a minute, so double this for a whole minute. Based on the logic we used above to calculate the first minute, which is "a", the following minutes will be (2a)/3 times "b", because "b" is the number of minutes the person spoke.

Adding these: a + (2a)/3 times b, so a + (2ab)/3 --> ***if you write down the fractions horizontally it makes much more sense, because you don't use the parenthesis.