For problem 2, it demonstrates an increase of 45%. This is simple, first find 45% of 140 by multiplying 140 by .45 which should get you to 63. Then because it is INCREASING by 45%, add 63 to 140 which equals 203, so your final answer is 203.
For question 4, it demonstrates a DECREASE of 80%, so we would use the same process but SUBTRACT instead. Find 80% of 75 by multiplying 75 by .8, which is equal to 60. Now, because it is a DECREASE of 80%