The adjoining figure shows a set of concentric squares. If the diagonal of the innermost square is 2 units and if the distance between the corresponding corners of any two successive square is 1 unit, then find the difference between the areas of the eighth and seventh squares, counting from the innermost square
B30 sq. units
D20 sq. units
Manish had fifteen pennies. He found some more and now he has thirty-three. Which number sentence could be used to find how many pennies he found?
DNone of these