What approximate value should come in place of the question mark (?) in the following equation?
16524 + 1492 - 250.0521?
Options:
(A) 1600
(B) 1800
(C) 1900
(D) 2400
(E) 1400

? 16 23 + 1490 250 1600 So the answer is: (A).

What is the units digit of the expression 14^715^4?
Options:
(A) 0
(B) 8
(C) 4
(D) 6
(E) 3

I think answer on this one should be B too. Since we know that 14^7>15^4, as Will said one should always check if the number is positive. So the answer is: (B).

A and B can do a work in 12 days, B and C in 30 days and C and A in 36 days. In how many days will the work be completed, if all three of them work together?
Options:
(A) 180/15
(B) 180/10
(C) 180/13
(D) 180/15
(E) 180/11

One day work of A and B = 1/12
One day work of B and C = 1/30
One day work of C and A = 1/36
2(A + B + C) = 1/12 + 1/30 + 1/36
2(A + B + C) = 13/90
(A + B + C) = 13/180
Number of days required = 180/13 days. So the answer is: (C).

How much more would Rs.20000 fetch, after two years, if it is put at 20% p.a. compound interest payable half yearly than if is put at 20% p.a. compound interest payable yearly?
Options:
(A) Rs.482
(B) Rs.424
(C) Rs.842
(D) Rs.512
(E) Rs.524
20000(11/10)4 - 20000(6/5)2 = 482 So the answer is: (A).