# Model Aptitude questions and answers for placement - Set 18

1)   How many 8's are present in the following sequence of numbers which are exactly divisible by both its preceding and following numbers ?

3  8  6  8  8  7  6  8  3  4  8  2  5  6  2  8  2  4  8  6  3  7  4  8  4  5  8  4

a. 5
b. 6
c. 2
d. Less than 4
e. None of these
 Answer  Explanation ANSWER: Less than 4 Explanation: 3 8 6 8 8 7 6 8 3 4 8 2 5 6 2 8 2 4 8 6 3 7 4 8 4 5 8 4 We want a group of 3 numbers with “8” at the centre such that it would be exactly divisible by both its preceding and following numbers. There are 3 such groups. (See the underlined groups above).

2)   There are 30 people in a party. If everyone is to shake hands with one another, how many hand shakes are possible?

a. 180
b. 256
c. 386
d. 435
 Answer  Explanation ANSWER: 435 Explanation: Total number of persons = n = 30Shakehands involve only 2 persons = r = 2 Number of shakehands = nCr = 30C2 30C2 = (30 * 29) /(2 * 1) = 435 nCr = (n!) / r! (n – r)! = 30! / 2! 28! = 435

3)   Two trains start at same time from two stations and proceed towards each other at the rate of 20 km/hr and 25 km/hr respectively. When they meet, it is found that one train has traveled 60 km more than the other. What is the distance between the two stations?

a. 620 km
b. 540 km
c. 460 km
d. 720 km
 Answer  Explanation ANSWER: 540 km Explanation: Let us assume that trains meet after 'x' hoursDistance = speed * TimeDistance traveled by two trains = 20x km and 25x km resp. As one train travels 60 km more than the other,25x – 20x = 605x = 60x = 12 hoursAs the two trains are moving towards each other, relative speed = 20 + 25 = 45 km/hrTherefore, total distance = 45*12 = 540 km.

4)   If Reena says, “Anjali's father Raman is the only son of my father-in-law Ramanand”, then how is Piyu, who is the sister of Anjali, related to Ramanand ?

a. Wife
b. Sister
c. Grand-daughter
d. Daughter
e. None of these
 Answer  Explanation ANSWER: Grand-daughter Explanation: Only son of Reena's father-in-law Ramanand is Reena's husband. So, Raman is Reena's husband and Anjali & Piyu are his daughter's, Thus, Piyu is Grand-daughter of Ramanand.

5)   An article costs Rs. 600. What should be the marked price of an article so that after 10% discount, the trader makes 20% profit?

a. Rs. 800
b. Rs. 950
c. Rs. 1100
d. Rs. 1040
 Answer  Explanation ANSWER: Rs. 800 Explanation: Cost price of article = Rs. 600Profit % = 20%Therefore,selling price of article = 120% of C.P.= (120 / 100) * 600 = Rs. 720Marked price = ?Discount % = 10%S.P. = Rs. 72090% of M.P. = S.P.90/100 * M.P. = 720M.P. = 720 * (100/90) = Rs. 800

6)   A and B enter into a partnership with respective capitals of Rs. 20,000 and Rs. 40,000. At the end of the year, the total profit is Rs. 33,000. If A receives Rs. 15,000 as both his salary and profit, then what is his salary?

a. Rs. 2000
b. Rs. 4000
c. Rs. 3500
d. Rs. 3000
 Answer  Explanation ANSWER: Rs. 4000 Explanation: A's capital : B 's capital20000 : 40000 = 1 : 2Since, the time period is fixed, the profit is distributed in the ratio of capital 1 : 2Profit of A = (1/3) * 33,000 = Rs. 11,000Salary of A = Rs. (15000 – 11000) = Rs. 4000

7)   Find the principal which yields a simple interest of Rs. 20 and compound interest of Rs. 21 in two years, at the same percent rate per annum?

a. Rs. 520
b. Rs. 480
c. Rs. 420
d. Rs. 200
 Answer  Explanation ANSWER: Rs. 200 Explanation: SI in 2 years = Rs. 20, SI in 1 year = Rs. 10 CI in 2 years = Rs. 21% rate per annum = [(CI – SI) / (SI in 1 year)] *100= [(21 – 20) / 20] * 100= 5 % p.a.Let the principal be Rs. XTime = T = 2 years% rate = 5% p.a. SI = (PRT/100)20 = (X*5*2) / 100X = Rs. 200

8)   If “*” is called “+”, “/” is called “*”, “-” is called  “/”, “+” is called “-”. 40/20 – 5 * 10 + 5 = ?

a. 170
b. 160
c. 150
d. 175
e. None of these
 Answer  Explanation ANSWER: None of these Explanation: Given : 40/20 – 5 * 10 + 5 = ?Substituting the coded symbols for mathematical operations, we get,40 * 20/5 +10 – 5 = ?40 * 4 + 10 – 5 = ?160 + 10 – 5 = ?170 – 5 = 165

9)   The speed of boat in still water is 20 km/hr. If it travels 26 km downstream and 14 km upstream in same time, what is the speed of the stream?

a. 4 km/hr
b. 5 km/hr
c. 6 km/hr
d. 7 km/hr
 Answer  Explanation ANSWER: 6 km/hr Explanation: Let X be speed of streamSpeed of boat downstream = (20 + X )Speed of boat upstream = (20 – X)It is given that boat takes same time to travel 26 km downstream and 14 km upstream[26/(20 +X)] = [14 / (20 – X)] 520 – 26 X = 280 + 14X 40X = 240X = 6 km/hr

10)   A traveler changes 150 pounds into rupees at the rate of Rs. 7000 for 100 pounds. He spends Rs. 9060 and changes the remaining amount back to pounds at the rate of 100 pounds to Rs. 7200. How many pounds will he get?

a. 18 pounds
b. 20 pounds
c. 25 pounds
d. 30 pounds
 Answer  Explanation ANSWER: 20 pounds Explanation: Amount of rupees for exchange of 150 pounds = (150/100)*(7000/1) = Rs. 10,500 Out of these Rs.10,500, traveler spent Rs. 9060Remaining balance in rupees = 10,500 – 9060 = Rs. 1440Now these Rs. 1440 are exchanged back to pounds with the rate of 100 pounds for Rs. 7200Amount in pounds = (1440 * 100) / 7200 = 20 pounds

11)   The average marks obtained by 100 candidates in an examination is 50. Find how many candidates have passed in the examination, if the average marks of candidates who passed is 70 and that of failed candidates is 20.

a. 90
b. 75
c. 60
d. 58
 Answer  Explanation ANSWER: 60 Explanation: Let the number of students who passed the examination be XNumber of students failed = (100 - X) Total marks of students who have passed = 70XTotal marks of 100 students = 100 * 50 = 5000Total marks of students who have failed = 20(100 – X) 20(100 – X) + 70X = 50002000 – 20 X + 70X = 500050 X = 3000X = 60

12)   Find the missing number

a. 40
b. 38
c. 39
d. 35
e. None of these
 Answer  Explanation ANSWER: 39 Explanation: We have :In first row, (5 * 6) – 2 = 30 – 2 = 28In second row, (9 * 9) – 4 = 81 – 4 = 77Thus,In third row, the missing number is (7 * 6) – 3 = 42 – 3 = 39