count number of duplicate words in 2 cells

cell A1 contains the text string 'black blue green red yellow grey pink'
cell B1 contains the text string 'black blue green orange brown white'

i need a formula that works out cell B1 has 3 words that occur in cell A1 and returns an answer of 3

thanks

Hi Haseeb,

This works but only if there is no data on subsequent rows. I have 100 rows of data and need to work it our for A1 and B1, A2 and B2 etc. Do you have a formula that is based on the single row?

Thanks

Ah I was using it for the 2nd row, sorted now... many thanks!