Question

There are numbers from 1 to 30. How many ways are there to select 3 numbers, which make a sum of even number?

Answer 1

@Mertsj

Answer 2

Shouldn't be too hard :)
Number of ways you can pick three even numbers + number of ways you can pick an even number and two odd numbers

Add them up
^.^

Answer 3

PeterPan

Answer 4

prettyboy20202

Answer 5

Oh, so even numbers:

\[C _{15}^{3}=455\]

Answer 6

No repetitions, I hope? :D

Answer 7

it is not said

Answer 8

Then, it's your call :)

Answer 9

and how to find a way to pick: 2even+odd?

Answer 10

Well, how many ways can you pick two odd numbers?
And how many ways can you pick ONE even number (out of 15 even numbers?)

Multiply them ^.^

Answer 11

oh, there is 15 ways to pick one even number, right?

Answer 12

two odd:

\[C _{15}^{2}=105\]

Answer 13

105+115=120?

Answer 14

is it correct?

Answer 15

Well, I think it is not, because the answer is 2030:D

Answer 16

Get 15 * 105

Answer 17

oh, right

Answer 18

i am so distracted today. Thank you a lot!

Answer 19

^.^