It is always important to set up problems in a way that most naturally chimes with the principles involved. 42% is the least number of male and Females who are 35 years old. So we have fraction of male plus fraction of female over Total number of make and female (M+F). This hardly requires much thin...

If you want 4 pairs of girls from 12 girls, the first pair comes from 12, 2nd pair comes from 10 ..... (12C2 x 10C2 X 8C2 X 6C2)/4! ( (G1 G2) ( G3 G4) (G5 G6)( G7G8)=(G5 G6)( G7G8) (G1 G2) ( G3 G4) ) and that is why you divide by 4! 12C4 means forming a group of 4 girls from 12. Four girls are not 4...

Re: Game of Pattern Recognition

You are over thinking Ian. Give it a second shot. No, he isn't. Of course, the "simplest" (which is a relative term in mathematics) solution is B, 18, which is solved according to a linear pattern relating to the given numbers. But as Ian stated, there are an infinite number of "patt...

Re: Plastic sleds

In the past, most children who went sledding in the winter snow in Verland used wooden sleds with runners and steering bars. Ten years ago, smooth plastic sleds became popular; they go faster than wooden sleds but are harder to steer and slow. The concern that plastic sleds are more dangerous is cl...

Since Z is a subset, I would find the Universal or Power Set. Let this be U. 1) says that Z is a multiple of 5. So what Universal set has as its elements only multiples of five. U= { …… -15, -10, -5, 0, 5, 10, 15, …..} Since this is the universal set and Z is infinite, any combination from this set ...