My answer is 21.
First I started with the circle and guessed it might be 3 but it was'nt so I tryed 4 and as the bottom row had to add up to 20 and there were 3 circles and 1 square and I thought the circle would equal 4 the square had to equal 8.On the another row there was 2circles 1square and 1triangle and that row had to add up to 22 so I worked out that the triangle must equal 6.
Then afterwards I found a row with 2squares and 2hexagons and that row had to add up to 30 and again I worked out because the 2squares added up to 16 and there was 14 left over till 30 that each hexagon must be worth 7.
Finally I added up the shapes in the row that we had to find out 4+4+7+6 equaled 21.
Lauren xx