A circular logo is enlarged to fit the lid of a jar. The new diameter is 50 per cent larger than the original. By what percentage has the area of the logo increased?
A. 25%
B. 50%
C. 100%
D. 125%
E. 140%
If the diameter of the old lid is 100, the diameter of the new lid will be 150.
This gives a ratio of 2 : 3
The areas of the lids will be in the ratio (2)2 : (3)2 . or 4 : 9
This represents an increase in area of 5units for every 4 units
5/4 is equivalent to 125%.