multiply a entire column, by another column

[manvest]

I want to multiply an entire column, by another column, and accumulate the results. Like this:

A	b	c
2	5	10
3	4	12
4	3	12
5	2	10

<tbody>
</tbody>

and then sum them. the result would be the sum of all the column c = 44.

how can I do it? how can I calculate c directly? do you know a special function available for doing so?

thank you. sorry if there are some mistakes, I am not english-speaker.

 

[mikerickson]

Try
=SUMPRODUCT(A1:A4, B1:B4)

 

[Aladin Akyurek]

Try...

=SUMPRODUCT(A2:A5,B2:B5)

 

[manvest]

so much thanks!