maths

[skillszone]

Find the smallest number in a GP whose sum is 38 and product 1728

[crofter]

skillszone Are you sure you have stated the correct figures here? I can get a GP (with only three terms whose product is 1728 and whose sum is 42, but not 38). The initial term is 6 and the constant ratio is 2 to yield the GP (over three terms) given by 6, 12 and 24.

Note 6 x 12 x 24 =1728 but 6 + 12 + 24 = 42

The solution should satrt with the factors of 1728 which are given by (2 ^ 6) x (3 ^ 3). This suggests using three terms in the GP with an initial term of 3 or 6.

[Grace Digger]

8 12 18

[crofter]

Nice one Grace. An initial term of 8 and constant ratio of 3. This was the only combination of factors of 2 and 3 that I didn't try before having to dash off to a meeting!

Don't you just hate it when work interferes with AnswerBank!

[Grace Digger]

What's a meeting?

[crofter]

Grace What luxury to be able to say that! :-)