Cost of Teaching... lowest possible option

[jefflad]

Hi,

I'd like to set-up a spreadsheet for teaching that I offer... it's basically only 2 (£14), 5 (£30) and 7 (£45) blocks of hours I offer and would like a formula to work out what is the cheapest for my clients.

For instance if a customer asked for 14 hours the cheapest would be 2x7 and not 5+5+2+2... is there such a formula?

J

[Special-K]

How do you get 3 x 5 + 2 ?
That's 17 hours
Surely it would be 2 x 5 + 2 ?

(Blimey, I hope you're not teaching maths!) :-)

[jefflad]

And I guess what would be helpful... if someone asked for a denomination in hours that was incorrect, it'd throw up an error?

i.e. 8 or 15 etc.

[jefflad]

How do you get 3 x 5 + 2 ?
That's 17 hours
Surely it would be 2 x 5 + 2 ?

(Blimey, I hope you're not teaching maths!) :-)

Yip... my fault, I'll edit it

[Special-K]

Yep 2 x 5 + 2 x2
It would seem I am in need of maths teaching as well :-)
Intriguing problem...thinking...

[jefflad]

ha... yeah, obviously not maths

[jason.b75]

For instance if a customer asked for 14 hours the cheapest would be 2x7 and not 5+5+2+2... is there such a formula?

3*5 costs the same as 2*7 so do you want to offer them what they asked for or the best value?

5 hours + 2 hours = 44, or 7 hours = 45

... if someone asked for a denomination in hours that was incorrect, it'd throw up an error?

i.e. 8 or 15 etc.

How would you determine that 8 and 15 are incorrect denominations?

8 = 4 x 2
15 = 5 x 3

Although some denominations may prove costly to the customer, 1 and 3 are the only denominations not possible from combinations of 2, 5 and 7.

I answered a similar question a couple of years ago, I'll have a look and see if I can find a copy of the test file (not on computer but might still have it on a flash drive), although I think, given the above observations, I don't think that it will work for your needs.

[jefflad]

Hi,

Just as what is asked... in case prices go up and I take into account the close costing... thanks

3*5 costs the same as 2*7 so do you want to offer them what they asked for or the best value?

5 hours + 2 hours = 44, or 7 hours = 45


How would you determine that 8 and 15 are incorrect denominations?

8 = 4 x 2
15 = 5 x 3

Although some denominations may prove costly to the customer, 1 and 3 are the only denominations not possible from combinations of 2, 5 and 7.

I answered a similar question a couple of years ago, I'll have a look and see if I can find a copy of the test file (not on computer but might still have it on a flash drive), although I think, given the above observations, I don't think that it will work for your needs.

[jason.b75]

Will have to give that some thought.

I couldn't find a copy of the old file, but from memory it would round up to most efficient, rather than what is asked for.

i.e. if customer asked for 6 hours, but 7 hours would cost less then it would suggest 7 instead.

Any ideas, Special-K?