Below are three aptitude questions not specific to a chapter. But these are general types of questions that can be expected on placement papers.

Question 1

In the General Body meeting of "Saidapet Friends Recreation Club", a discussion about improving infrastructure was held between members. At the end of the discussion, the Secretary said, "Costs to the Club will Rs 31200 and I propose that this expense be equally beared by the members". Everyone agreed to the proposal. However, after the infrastructure improvement project, four members resigned from the club leaving the remaining members to pay an extra Rs 260 each.How many members did the Recreation Club originally have?

(a) 24 (b) 32 (c ) 36 (d) 38

Answer : a) 24

Solution:

Such types of questions can be solved directly or backwards inspecting one option at a time. Now let us try backward method of going by options.
Let us try option (a) to check if it is the correct answer.
Total expense is Rs. 31200 and we have assumed 24 members (as per option a). Each member would had agreed to pay Rs 31200 / 24 = Rs. 1300 each. If 4 members had resigned there would have been 20 members. Therefore the actual expense of every member would be Rs 31200 / 20 =1560. 1560 is 260 more than 1300 initially agreed. This fits the data in question perfectly. Hence option a is the right answer.

Question 2

Imagine a sanctuary with lot of rare varieties of birds and animals. The forest officials were counting the number of four legged animals and birds in a particular region of the sanctuary. The number of animals was 11 more than the number of birds. If there were as many animals as there were birds and as many birds as there were animals, the total number of legs get reduced by one fifth (1/5). How many number of birds were there ?

(a) 22 (b) 18 (c) 11 (d) 14

Answer : c) 11

Solution:

Let the number of birds be x. Then, as per data, number of animals would be x + 11.
Every bird has two legs and every animal has four legs.
Total number of legs of animals and birds in the region of counting, Toriginal =2x + 4(x + 11) = 6X + 44 legs.
Total number of legs if number of birds and animals were interchanged, Tinterchanged = 2(x + 11) + 4x = 6x + 22 legs

Second part of the question says that if number of animals and birds were interchanged, the number of legs would be reduced to 1/5th.
This means Tinterchanged is four fifth's of Toriginal
Or 6x + 22 = 4 / 5 (6x + 44)
30x + 110 = 24x + 176
6x = 66
or x = 11 = Total number of birds in the region

Question 3

During first week of June, professors and students of Shri Ramanuja College planned a picnic to Mahabalipuram. Normally the college reopens during second week of June every year, and the faculty and students start the academic year with a picnic. All the participants contribute equally towards the expenses every time. When they planned to contribute 20% more than previous year’s contribution ( number of participants being same last year and this year initially ) they found that the amount each has to contribute is equal to the total number of persons planning to go for picnic. One day before picnic, 15 persons withdrew from the plan due to personal reasons. On the day of picnic, another 10 could not turn up. The actual contribution increased by 33 1/3% than the planned contribution. How many were initially interested in the picnic?

(a)125 (b) 100 (c) 133.33 (d) 110

Answer : b) 100

Solution:

Let the original number of participants be P.
According to question data, each would had agreed to contribute Rs. P.
Actually planned total contribution = Number of original members X Contribution per member = P x P = P² ...(A)
15 persons withdrew a day before picnic and another 10 withdrew on the day of picnic.
Therefore, total number of participants who turned up for Picnic = P - (15 + 10) = P - 25

To pay the total expense of Rs. P² (refer equation A), every member had to contribute 33 1/3% or 100/3% more than planned individual contribution of Rs. P
That is the actual contribution per member = P + Px100/3% = P + P/3 = 4P/3
Actual total contribution = Number of present members X Actual contribution per member = (P - 25)(4P/3) ...(B)

Since actual total contribution should match the amount of initially planned total expense, values of equations A and B must be same.
i.e (P - 25)(4P/3) = P²
Or (4P²-100P) / 3 = P²
Or 4P²-100P = 3P²
Or P² = 100P
Or P = 100
Therefore original number of participants = 100
So, option (b) is correct.