Thursday

December 18, 2014

December 18, 2014

Posted by **Emma** on Saturday, July 7, 2007 at 8:19am.

I got the answer of 31 students. am i right? if i am not,could someone please show me how to figure this out?

Look at the sums:

ways to get sum of 1...10

ways to get sum of 2....20,11

How can three students get 3> 2,0;1,1, disallow 0,2

How can three students get 4> 4,0;22, 13, 31

get 5? 32, 23, 14, 41, 50

get 6 60, 51,15,24,42, 33

get 7 25, 16, 52, 61, 70, 43,34

get 8 17,71, 80, 62, 26, 35, 53,44

get 9 45, 54, 63,36, 27,72,`18,81,90

get 10 19,91,28,82,37,73,46,64, 55

get 11 29,92,38,83,74,47,56,65

notice the pattern...the ways to get a sum is always Sum until 9, then it is receeding in order.

get 12 ...7 ways (39,93,48,84,57,75, 66

get 13 six ways

get 14 five ways

get 15 four ways

get 16 three ways

get 17 two ways

get 18 one way.

Ok, then to have three in one sum, you will have two single sums, 15 of two sums, and one of three sums.

Number kids: 2 + 15*2 + 1*3

check my thinking.

- maths -
**ugen**, Sunday, July 29, 2012 at 8:55pm31 students

**Answer this Question**

**Related Questions**

Math - A math teacher wishes to use groups of 5 and/or 7 students for a class ...

Maths - A school has eleven Year 9 Maths classes of 27 students. Each class has ...

math equation - At east end middle school, twice as many students study spanish ...

Maths - A mathematics class has 200 members. If there is 12% absentee rate per ...

maths - On children's day, a teacher brought 63 erasers and 147 sweets to ...

maths - Set it up this way: Let the number of students be x let the number of ...

Math - A teacher is choosing 4 students from a class of 30 to represent the ...

Algebra 2 - A teacher is choosing 4 students from a class of 30 to represent the...

maths - 3/5 of the students are girl and number of boys are 200 in a class. Find...

Math - Mr. White notices that of the 30 students in his science class, 18 are ...