Answer:
Part a)133.3%
Part b)112.5%
Explanation:
Part a) We want to express 2 years as a percentage of 18 months.
Make sure both quantities are of the same units.
1 year =12 months
This means
2 years =24 months.
We want to express 24 months as a percentage of 18 months.
The number that comes after of will be in the denominator.

Part 2)
We want to express 225mm as a percentage of 20cm.
10mm= 1 cm
This means
200mm= 20cm
We want to express 225mm as a percentage of 200mm
