perplexus.info :: Just Math : Find the formula

Find the formula (Posted on 2024-04-10)

f(a,b) is defined by the following table:
f(2,3)=10,
f(3,7)=28,
f(4,5)=33,
f(5,8)=61,
f(6,7)=73,
f(7,8)= ???

Fill in the last value of f(a,b), and derive its formula.

No Solution Yet Submitted by Ady TZIDON

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re: Solution - with some help from previous posts

| Comment 4 of 8 |

(In reply to Solution - with some help from previous posts by Kenny M)

My previous post was a silly error. This one works, but likely is not the intended solution

f(a,b)=a^2+ab-(a-1)*floor(a/5+.5)

then f(7,8)=99

I feel like this is similar to fitting a "x" degree polynomial to x+1 ordered pairs.

Posted by Kenny M on 2024-04-10 20:20:01

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