Multiplying columns of different length

[lightbucket]

I'd like to multiply all the values in one column, with say 5 values, by all the values in a second column with say 3 values. Can you do this? So I'd expect 15 answers in Col C, or maybe as a 5*3 array.

Col A	Col B
1	10
2	20
3	30
4
5

 

[dreid1011]

Welcome to the forum. You can use the MMULT function, but you have to transpose the second column like this:

Book1
	A	B	C	D	E	F
1	1	10		10	20	30
2	2	20		20	40	60
3	3	30		30	60	90
4	4			40	80	120
5	5			50	100	150
Sheet1

Cell Formulas
Range	Formula
D1:F5	D1	=MMULT(A1:A5,TRANSPOSE(B1:B3))
Dynamic array formulas.

Add TOCOL for a single column:

Book1
	D
7	10
8	20
9	30
10	20
11	40
12	60
13	30
14	60
15	90
16	40
17	80
18	120
19	50
20	100
21	150
Sheet1

Cell Formulas
Range	Formula
D7:D21	D7	=TOCOL(MMULT(A1:A5,TRANSPOSE(B1:B3)))
Dynamic array formulas.

 

[Cubist]

Another option.

Book1
	A	B	C	D	E	F	G	H
1	1	10		10	20	30		10
2	2	20		20	40	60		20
3	3	30		30	60	90		30
4	4			40	80	120		20
5	5			50	100	150		40
6								60
7								30
8								60
9								90
10								40
11								80
12								120
13								50
14								100
15								150
Sheet5

Cell Formulas
Range	Formula
D1:F5	D1	=A1:A5*TOROW(B1:B3)
H1:H15	H1	=TOCOL(A1:A5*TOROW(B1:B3))
Dynamic array formulas.

 

[lightbucket]

Excellent, and thanks for all the alternatives. I've learnt a lot.
Many thanks