Consider the converses:
a) If two planes have no points in common, then they are parallel. (true)
b) If a point lies on the y-axis, then it has x-coordinate 0. (true)
c) If two angles have the same measure, then they are congruent. (true)
d) If a figure has four sides, then it is a square. (FALSE) (A figure with 4 sides may not even be a plane figure.)
Non-calculator
Method
You divide both sides by 10 to get 10%
You divide by 10 to get 1%
Now you divide by 2 to get 0.5 (or 1/2 of 1)
You can find 2% by multiplying 2 to 1% and 2
Now you need to add the 10% with 0.5% and 2% which give you 12.5%.
Now you takeaway 25 from 200
Decrease 200 by 12.5%