Important Aptitude questions asked in Amazon

Practice important Aptitude questions asked in Amazon

1. A function f(x) is defined as f(x) = f(x - 2) - x(x + 2) for all the integer values of x and f(1) + f(4) = 0. What is the value of f(1) + f(2) + f(3) + f(4) + f(5) + f(6)?
   
   1. 0
   2. 89
   3. -89
   4. None of these
   Answer: Option C
   Let S = f(1) + f(2) + f(3) + f(4) + f(5) + f(6)
   As f(1) + f(4) = 0, therefore S = f(2) + f(3) + f(5) + f(6) ------ (1)
   f(2) = f(0) - 8
   f(3) = f(1) - 15
   f(4) = f(2) - 24 = f(0) - 32
   f(5) = f(3) - 35 = f(1) - 50
   f(6) = f(4) - 48 = f(0) - 80
   Put the above values in equation (1), we get
   S = f(0) - 8 + f(1) - 15 + f(1) - 50 + f(0) - 80
   S = 2(f(0) + f(1)) - 153 ------ (2)
   As we already know f(1) + f(4) = 0 ⇒f(1) + f(0) - 32 = 0 ⇒f(1) + f(0) = 32
   Putting this value in equation 2, we get S = 2(32) - 153 = -89
   So, Ans is option C.
2. In ΔABC, the internal bisectors of ∠ABC and ∠ACB met at I and ∠BAC = 50°. The measure of ∠BIC is
   
   1. 105°
   2. 115°
   3. 125°
   4. 130°
   Answer: Option B
   I is the In-centre
   So, ∠BIC = 90° + 1/2 ∠BAC
   = 90° + 1/2 × 50 = 115°
3. The difference between [3/5] of [2/3] a number and [2/5] of[1/4] of the same number is 288. What is the number?
   
   1. 960
   2. 850
   3. 895
   4. 955
   Answer: Option A
   Let the no. Be [3/5] x [{2/3}x]-[2/5] x [1/4]x,then = 288 Solving it we will get 960
4. A, B, C and D are four consecutive odd numbers and their average is 42. What is the product of B and D? 
   
   1. 1860
   2. 1890
   3. 1845
   4. 1677
   5. None of these
   Answer: Option C
   As diff. Is same so average should lie between B and C so B is 41 & C is 43 so D must be 45 as we have to find the product of B and D so it would be 1845
5. The cost price of item A, Item A was sold at a profit of 10% and Item B was sold at a loss of 20%. If the respective ratio of selling price of items A and B is 11:12, what is the cost price of item B?
   
   1. Rs.450/-
   2. Rs.420/-
   3. Rs.400/-
   4. Rs.350/-
   5. Rs.480/-
   Answer: Option A
   The cost price of item B is Rs. 150/- more than the Let us assume cost price of A= X
   So that Cost price of B= X+150.
   SP of A= X*1.1
   SP of B=(X+150)*0.8
   Given that
   SPA: SPB
   11:12
   So that 1.1X/(X+150)*0.8= 11/12
   X=300
   CP of B= 300+150=450
   Answer is 450.

6. A sum of Rs 731 is divided among A, B and C such that 'A' receive 25% more than 'B' and 'B' receive 25% less than 'C'. What is C's share in the amount?
   
   1. Rs. 172
   2. Rs. 200
   3. Rs. 262
   4. Rs. 258
   5. None of these
   Answer: Option E
   A + B + C = 731 ..... (i)
   A = 1.25B, gives A = 1.25 * 0.75 C = 0.9375 C....(ii)
   B = 0.75C....(iii)
   Using (ii) and (iii) in (i) we get
   0.9375C + 0.75C + C = 731, gives C = 272.
   So option E is the answer.
7. In how many different ways can letters of the word "PRAISE" be arranged? 
   
   1. 720
   2. 610
   3. 360
   4. 210
   5. None of these
   Answer: Option A
   As total number of alphabets in PRAISE are 6, so total no. of ways is 6!=720 So option A is the answer
8. If the numerator of a fraction is increased by 150% and the denominator of the fraction is increased by 300%, the resultant fraction is [5/18]. What is original fraction?
   
   1. 4/9
   2. 4/5
   3. 8/9
   4. 8/11
   5. None of these
   Answer: Option A
   Let the fraction be [n/d] & after that it becomes [2.5n/4d]=5/18 . So we get the result as [4/9]
9. A car covers the first 30 km of its journey in 45 minutes and the remaining 25 km in 30 minutes. What is the average speed of the car?
   
   1. 60
   2. 64
   3. 49
   4. 48
   5. None of these
   Answer: Option E
   Total distance/Total time =(30+25)/[(3/4)+(1/2)]
   Average Speed=44kmph
10. Four examiners can examine a certain number of answer papers in 10 days by working for 5 hours a day. For how many hours a day would 2 examiners have to work in order to examine twice the number of answer papers in 20 days?
    
    1. 8
    2. 7.5
    3. 10
    4. 8.5
    5. None of The above
    Answer: Option C
    

    Examiners	Days	Hours/Day	Papers
    4	10	5	x
    2	20	?	2x

    So, we required number of hours = so optionC is the answer
    Using chain rule,
    (4×10×5)/X= (2×20×Y)/2X
    X=10 hrs/day

Source: Hitbullseye