The length of a rectangle is increased by 20% and its breadth is decreased by 20%. What is the effect on its area?
Options:
(A) 1288
(B) 9600
(C) 1000
(D) 10000
(E) 2887

100 * 100 = 10000
120 * 80 = 9600 So the answer is: (B).

A light has a rating of 110 watts, it is replaced with a new light that has 30% higher wattage. How many watts does the new light have?
Options:
(A) 143
(B) 145
(C) 156
(D) 134
(E) 100

Final number = Initial number + 30%(original number) = 110 + 30%(110) = 110 + 33 = 143. So the answer is: (A).

189. The inside dimensions of a rectangular wooden box
are 12 inches by 14 inches by 16 inches. A cylindrical
canister is to be placed inside the box so that it stands
upright when the closed box rests on one of its six
faces. Of all such canisters that could be used, what is
the radius, in inches, of the one that has maximum
volume?
Options:
(A) 3
(B) 4
(C) 5
(D) 6
(E) 7

Since the radius is squared, the biggest volume cylinder will have the biggest possible radius. To achieve that, let the smaller dimension of the rectangular box be the height. So, it will have 16x14width x length. The biggest cylinder must fit both dimensions, so it must have at most a diameter of 14, so the radius will be 7. So the answer is: (E).

Using all the letters of the word "THURSDAY", how many different words can be formed?
Options:
(A) 8
(B) 8!
(C) 7!
(D) 7
(E) 5
Total number of letters = 8
Using these letters the number of 8 letters words formed is P = 8!. So the answer is: (B).