Match a condition and multiply columns

Tab 1

Column A Column B

John 50
Mary 50
Edward 50


Tab 2

John 12
Mary 10
Edward 10
....
....

etc

I need to match John from Tab 2 to John from Tab 1 and multiply what ever is in column 2 in Tab 2 with column 2 from Tab 1.

so I would get the result

John 600
Mary 500

etc

Try

=VLOOKUP("John",Sheet1!$A$1:$B$10,2,0)*VLOOKUP("John",Sheet2!$A$1:$B$10,2,0)

edit ranges/sheetnames to suit. Also you can replace "John" with a cell reference containing the name.