*MATH* Four friends are all close in age but wish to sit themselve in order from youngest to oldest.?

Question

Four friends are all close in age but wish to sit themselve in order from youngest to oldest. Kim and Andrea have a combined age of 55, and Derek and Andrea have figured out that their combined age is 59. Michelle's age is equal to 32. So if Michelles age is half way between Derek and Kims what order should they sit in?
A) Derek Michelle Andrea Kim
B) Derek Andrea Michelle Kim
C) Andrea Derek Michelle Kim
D) Kim Michelle Andrea Derek
E) Andrea Kim Michelle Derek

Answer 1

E

Michelle = 32

Derek has to be older than Kim, because Andrea + Derek is greater than Andrea + Kim, so

Derek = 32 + x
Kim = 32 - x

As the 55 and 59 are 4 apart and as Andrea is the same age with both, that means their ages have to be four years apart, so Derek must be 34, and Kim 30, with x being 2, as Michelle's age is halfway between them. This makes Andrea 25.

Andrea: 25
Kim: 30
Michelle: 32
Derek: 34

Answer 2

She's right it's E:
if Michelle is 32, and her age is exactly halfway between Derek and Kim, then we know that someone is 34 and the other is 30 (32 is the halfway point between the 2). Since Andrea combined her ages with Kim and Andrea, it gets easy.
Andrea + Kim = 55
Andrea + Derek = 59 (Derek is the older person).
Since We know Michelle is halfway between Kim and Derek-and we know Derek is older than Kim...the order goes:

Kim, Michelle, Derek

And since none of your answers have Andrea listed as last-your only choices are D and E.

So where is Andrea...
hmm...Michelle is 32...so let's think if say 55-32=23...so at least Andrea is 25 right? And since you only have the choices of D or E...Andrea can't be older than Michelle-so it has to be E...

Your answer is E!

Answer 3

E

A + K = 55

D + A = 59

M = 32

32 = (D + K)/2
32 = [(59 - A) + (55 - A)] ÷ 2
32 = 114 - 2A
32 = 57 - A
A = 25

So Andrea is 25, Kim is 30 (55 -25), Michelle is 32 (given) and Derek is 34 (59 - 25)