IQ test need help

[rbbrg]

john likes 400 but not 300, he likes 100 but not 99, he likes 3600 but not 3700. Which of theses four does he like?

900

1000

1100

1200

[ermintrude35]

Look at the factors of numbers he likes and dislikes.

400 = 2x2x2x2x5x5;
100 = 2x2x5x5;
2500 = 2x2x5x5x5x5;

300 =3x5x5;
99 = 3x3x1x1;
2400 = 2x2x2x2x2x3x5x5.

The numbers he likes are all perfect squares and are only made up of 2's and 5's. Based on the given information there are two logical answers:

900, since it is a square, and
1000, since 1000 = 22255.

[ermintrude35]

Look at the factors of numbers he likes and dislikes.

400 = 2x2x2x2x5x5;
100 = 2x2x5x5;
2500 = 2x2x5x5x5x5;

300 =3x5x5;
99 = 3x3x1x1;
2400 = 2x2x2x2x2x3x5x5.

The numbers he likes are all perfect squares and are only made up of 2's and 5's. Based on the given information there are two logical answers:

900, since it is a square, and
1000, since 1000 = 2x2x2x5x5.

[kempie]

A comprehensive answer by ermintrude35, but I like to break things down into simple pieces.

First thing I did was divide all numbers by 100.

Likes     = 4, 1, 36    (all perfect squares)

Dislikes = 3, .99, 37  (no immediately discernible pattern)

Choices = 9, 10, 11, 12  (9 is a square)

therefore I'd go with 900

[THECORBYLOON]

ermintrude I'm a wee bit confused by yir reasoning. Where does 2500 come in to it? and 300 doesn't =3x5x5 

[biley]

Has to be 900 as kempie says. ermintrude35 has unfortunately misread the question and 3600 ( a number john likes) cannot be broken down into 2's and 5's.

Therefore it has to be the key fact that all the numbers John likes are squares and the only one of the four other choices is a square - giving 900 as the answer. 

[kev100]

John likes numers that have nice round square roots

400 sq r. 20
100 sq r. 10
3600 sq r. 60
900 sq r. 30

all the others give a number followed by .756348484 or similar.

[kev100]

Or is that what everybody else meant?