5th math
posted by pat .
what is the least common multiple (LCM)for 15 and 45?
There are 16 girls in a class of 36 student. which expression could be used to determine the number of boys (b) in the class?
please! help i think this too hard for 5th grade math. this suppose to be for 10th or college level instead of me..i don't even understnd this problem.

These are not college or high school problems. They are part of the normal 5th grade curricula.
Check this site for LCM instructions.
http://www.mathsisfun.com/leastcommonmultiple.html
Let x = the number of boys in the class.
36  16 = x 
I agree with Ms. Sue. These are definitely in a good 5th grade math curriculum. My granddaughter is in 5th grade this year, and she has had this level of work for over a year now.

can you show how to do the median ?
what is the median for the following numbers?
142,83,65,178,14,78.
i think 83 is the answer.
36/16=B THE ANSWER FOR EXPRESSION FOR .36 STUDENTS 36/16=20 BOYS THE ANSWER 
http://www.purplemath.com/modules/meanmode.htm
"The median is the middle number. In this example, the numbers are already listed in numerical order, so I don't have to rewrite the list. But there is no "middle" number, because there are an even number of numbers. In this case, the median is the mean (the usual average) of the middle two values: (2 + 4) ÷ 2 = 6 ÷ 2 = 3"
14, 65, 78, 83, 142, 178
So you need to find the average (mean) between 78 and 83. How will you do that? 
LCM=3
let x=total students
let y=total girls
let z=total boyz
z=xy
z=3616
z=10 
Visitors to an art musuem were asked to
name a favorite type of art.Pottery was
named by 9/40 of the visitors, paonting
was named by 2/5, and sculpture was
named by 3/8. What was the favorite type of art of most visitors ?
THIS IS SOOOOO HARD !!!! PlEaSe HeLp 
lcm=45
3616=boys
By the way i learned this before 5th grade 
This seems very easy..