[Ques]: A multiple choice test consists of 4 questions, and each question has 5 answer choices. In how many ways can the test be completed if every question is unanswered?
Options:
(A) 24
(B) 120
(C) 625
(D) 720
(E) 1024
*Ans*: (C)
--CoT--: 5 choices for each of the 4 questions, thus total of 5*5*5*5 = 5^4 = 625 ways.

[Ques]: Ravi can do a piece of work in 20 days while Prakash can do it in 40 days. In how many days will they finish it together?
Options:
(A) 5 7/9 days
(B) 6 7/9 days
(C) 5 1/9 days
(D) 5 7/2 days
(E) 4 7/9 days
*Ans*: (A)
--CoT--: 1/20 + 1/40 = 3/40
40/7 = 5 7/9 days

[Ques]: Solve:-
333 x 333 x 333 + 555 x 555 x 555 = ?(333 x 333 - 333 x 555 + 555 x 555)
Options:
(A) 888
(B) 333
(C) 555
(D) 988
(E) 889
*Ans*: (A)
--CoT--: Given Exp. = (a3 + b3) = (a + b) = (333 + 555) = 888(a2 - ab + b2)

[Ques]: The sale price shirts listed for Rs.400 after successive discount is 10% and 5% is?
Options:
(A) 280
(B) 290
(C) Rs.342
(D) 250
(E) 253
*Ans*: (C)
--CoT--: 400*(90/100)* (95/100) = 342