 # Simple (?) number puzzle 39+91>>>100+60

(Well…it makes sense to me. If it’s not right, how about you try to figure out MY answer!!) :s Here’s my attempt…

The pattern is (look at the sum and product of each side) : -

A + B -> X + Y

where X + Y = A + B + 10
and A * B = X * Y

Check this…

1’st line
10 * 21 = 6 * 35 = 210
10 + 21 = 31 -> 5 + 35 = 41 (31 + 10)

2’nd line
21 * 34 = 51 * 14 = 714
21 + 35 = 55 -> 51 + 14 = 65 (55 + 10)

So,

39 + 91 -> X + Y

where X + Y = 130 + 10 = 140
and X * Y = 39 * 91 = 3549

This yields a very ugly quadratic equation with even uglier roots…

X^2 - 140X + 3549 = 0

This doesn’t give a very pretty solution though =>

39 + 91 -> 106.7559519 + 33.2440481 So, perhaps my assumptions were wrong… :s

Definitely something to do with factors:

10=25
21=3
7

Therefore solution = (23) = 6 and (57) = 35

21=37
34=2
17

Therefore solution = (317) = 51 and (72) = 14

39=313
91=7
13

The only thing is, I don’t know which order to multiply in. So solution could be:

(21,169) or (39,91) [identical]

Unless someone can work out how they picked the ordering.

[quote=“daasgrrl”]Definitely something to do with factors:

10=25
21=3
7

Therefore solution = (23) = 6 and (57) = 35

21=37
34=2
17

Therefore solution = (317) = 51 and (72) = 14

39=313
91=7
13

The only thing is, I don’t know which order to multiply in. So solution could be:

(21,169) or (39,91) [identical]

Unless someone can work out how they picked the ordering.[/quote]
:bravo: :bravo: :bravo:   :bravo: :bravo: :bravo:

Daasgrrl, well done! I managed to check the solution on the site the puzzle came from, it needs some translation but the numbers are there …

[quote]Okee, hier de oplossing: als we de eerste regel bekijken, zien we dat de getallen 10 en 21 maar op

:bravo: Well done ! Also true for reading Dutch text to verify solution.