why is the answer c
#help
rigid bane
vestal cradleBOT
gleaming wadi
it doesn't make sense if you don't balance the classrooms equally
which they don't say
but otherwise it just makes sense
if there's 13 people in each room you can be sure there's a repeat
this is not perms and combs
vestal cradleBOT
help
rigid bane
this is not perms and combs
oops my bad, its pigeonhole principle right
gleaming wadi
yes
gleaming wadi
so like you need to solve this for one room, which gives 13, and you multiply it by 4
each room separately satsifies the condition, as long as you keep the number equal
if you don't assume the number in each room is as close to equal as possible, there's no number that works, anything is "too small"
rigid bane
each room separately satsifies the condition, as long as you keep the number equ...
ohh ok i get it
i misread the qs as at least 2 students with the same bday in any of the 4 classrooms mb
alpine token
If you have 12 or less student on a classroom it guarantee that every student in the classroom has the unique month of birth
Therefore, you must have at least 13 students in each of the 4 classrooms
Therefore, you must have at least 52 students
This is a lower estimate
Let's get a higher estimate
Every student can be associate with a pair (N, M) of numbers: number of a classroom and month of birth
We have 48 pairs total to occupy
4 of them must be occupy twice
48 + 4 = 52
This is a higher estimate
The answer is C.
rigid bane
The answer is C.
that explanation makes a lot of sense, thank you
limber sequoia
.close