TCS
Company
(1) In how many ways can you select at least one chocolate, one pastry and one biscuit from 2 chocolate,3 pastries and 4 biscuits?
(a) 350 (b)315 (c)250 (d) 275
(2)1!+2!+3!+…………………………….+68!.what is the digit at tenth place?
(a)0 (b)1 (c)5 (d) 7
(3)In a sequence of numbers,the sum of the first n terms is equal to 11n^2+10n.What is the sum of the 2nd,4th and 6th in the sequence?
(a)250 (b)300 (c)261 (d) cant say
Read Solution (Total 8)
-
- ans of 1st is 315 ways
bcz no.of ways of selecting 1 or more items frm n items is 2^n-1
apply dis
for chocolate 2^2-1=3
for pastries 2^3-1=7
for biscuits 2^4-1=17
now 3*7*15=315
- 11 years agoHelpfull: Yes(21) No(0)
- sum of first n terms=11n^2+10n
sum of first(n-1) terms=11(n-1)^2+10(n-1)
calculate it =11n^2-12n+1
nth term=sum of n terms-sum of n-1 terms
nth term=22n-1
hence find 2,4 6 term by putting n=2,4.....
ans =261 - 11 years agoHelpfull: Yes(11) No(0)
- -->(3) 1st n terms sum = n(11n+10)
then calculate for 1st term we get = 21
----"""------------2nd------------ = 43
-------------------3.......=65
------4------=87
---5-----=199
----6-----=131
then sum of 2nd + 4th + 6th =261
Ans: 261 - 11 years agoHelpfull: Yes(5) No(0)
- 2nd one :-
as the no. of zeros from 10! - 68! consist of two or more zeros at two last places thus now we have to consider only 1! + 2! + ...+ 9! =....13 where .... represents some value. Thus digit at tenth place is 1. Ans :1 - 11 years agoHelpfull: Yes(3) No(3)
- (3) s(n) = 11n^2+10n
s(n-1) = 11n^2 -12n +1
As we know that
an=s(n) - s(n-1)=22n-1
thus we get values as s2 s4 s6 as 43 87 131 thus suming we get 261 - 11 years agoHelpfull: Yes(2) No(0)
- i dont know
- 11 years agoHelpfull: Yes(1) No(10)
- average of 1st n numbers=11n+10.......(1)
averafe of 2nd,3rd,4th number=sum(2nd+3rd+4th)/3........(2)
[sum(2nd+3rd+4th)/3]+(n-3)=11n+10
sum(2nd+3rd+4th)+3n-9=33n+30
sum(2nd+3rd+4th)=30n+39 - 11 years agoHelpfull: Yes(0) No(3)
- nmKDO GOkg nlkg n
- 4 years agoHelpfull: Yes(0) No(0)
TCS Other Question
28a + 30 b +31c =365
find a+b+c if a.b.c are natural number
Note: These are not sample questions, but questions that explore some of the concepts that
may be used. The intention is that you should get prepared with the concepts rather than just
focusing on a set of questions.
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1. What are the total number of divisors of 600(including 1 and 600)?
a. 24
b. 40
c. 16
d. 20
2. What is the sum of the squares of the first 20 natural numbers (1 to 20)?
a. 2870
b. 2000
c. 5650
d. 44100
3. What is∑
(
), where
is the number of ways of choosing k items from 28
items?
a. 406 *
b. 306 *
c. 28 *
d. 56 *
4. What is ∑
(
) where
is the number of ways of choosing k items from 28
items?
a.
b.
c.
d.
5. A call center agent has a list of 305 phone numbers of people in alphabetic order of names
(but she does not have any of the names). She needs to quickly contact Deepak Sharma to
convey a message to him. If each call takes 2 minutes to complete, and every call is
answered, what is the minimum amount of time in which she can guarantee to deliver the
message to Mr Sharma.
a. 18 minutes
b. 610 minutes
c. 206 minutes
d. 34 minutes6. The times taken by a phone operator to complete a call are 2,9,3,1,5 minutes respectively.
What is the average time per call?
a. 4 minutes
b. 7 minutes
c. 1 minutes
d. 5 minutes
7. The times taken by a phone operator to complete a call are 2,9,3,1,5 minutes respectively.
What is the median time per call?
a. 5 minutes
b. 7 minutes
c. 1 minutes
d. 4 minutes
8. Eric throws two dice, and his score is the sum of the values shown. Sandra throws one die,
and her score is the square of the value shown. What is the probability that Sandra’s score
will be strictly higher than Eric’s score?
a. 137/216
b. 17/36
c. 173/216
d. 5/6
9. What is the largest integer that divides all three numbers 23400,272304,205248 without
leaving a remainder?
a. 48
b. 24
c. 96
d. 72
10. Of the 38 people in my office, 10 like to drink chocolate, 15 are cricket fans, and 20
neither like chocolate nor like cricket. How many people like both cricket and chocolate?
a. 7
b. 10
c. 15
d. 18
11. If f(x) = 2x+2 what is f(f(3))?
a. 18
b. 8
c. 64
d. 1612. If f(x) = 7 x +12, what is f-1(x) (the inverse function)?
a. (x-12)/7
b. 7x+12
c. 1/(7x+12)
d. No inverse exists
13. A permutation is often represented by the cycles it has. For example, if we permute the
numbers in the natural order to 2 3 1 5 4, this is represented as (1 3 2) (5 4). In this the
(132) says that the first number has gone to the position 3, the third number has gone to
the position 2, and the second number has gone to position 1, and (5 4) means that the
fifth number has gone to position 4 and the fourth number has gone to position 5. The
numbers with brackets are to be read cyclically.
If a number has not changed position, it is kept as a single cycle. Thus 5 2 1 3 4 is
represented as (1345)(2).
We may apply permutations on itself If we apply the permutation (132)(54) once, we get
2 3 1 5 4. If we apply it again, we get 3 1 2 4 5 , or (1 2 3)(4) (5)
If we consider the permutation of 7 numbers (1457)(263), what is its order (how many
times must it be applied before the numbers appear in their original order)?
a. 12
b. 7
c. 7! (factorial of 7)
d. 14
14. What is the maximum value of x3y3 + 3 x*y when x+y = 8?
a. 4144
b. 256
c. 8192
d. 102
15. Two circles of radii 5 cm and 3 cm touch each other at A and also touch a line at B and C.
The distance BC in cms is?
a. 60
b. 62
c. 68
d. 64
16. In Goa beach, there are three small picnic tables. Tables 1 and 2 each seat three people.
Table 3 seats only one person, since two of its seats are broken. Akash, Babu, Chitra,
David, Eesha, Farooq, and Govind all sit at seats at these picnic tables. Who sits with
whom and at which table are determined by the following constraints:
a. Chitra does not sit at the same table as Govind.
b. Eesha does not sit at the same table as David.
c. Farooq does not sit at the same table as Chitra.d. Akash does not sit at the same table as Babu.
e. Govind does not sit at the same table as Farooq.
Which of the following is a list of people who could sit together at table 2?
a. Govind, Eesha, Akash
b. Babu, Farooq, Chitra
c. Chitra, Govind, David.
d. Farooq, David, Eesha.
17. There are a number of chocolates in a bag. If they were to be equally divided among 14
children, there are 10 chocolates left. If they were to be equally divided among 15
children, there are 8 chocolates left. Obviously, this can be satisfied if any multiple of 210
chocolates are added to the bag. What is the remainder when the minimum feasible
number of chocolates in the bag is divided by 9?
a. 2
b. 5
c. 4
d. 6
18. Let f(m,n) =45*m + 36*n, where m and n are integers (positive or negative) What is the
minimum positive value for f(m,n) for all values of m,n (this may be achieved for various
values of m and n)?
a. 9
b. 6
c. 5
d. 18
19. What is the largest number that will divide 90207, 232585 and 127986 without leaving a
remainder?
a. 257
b. 905
c. 351
d. 498
20. We have an equal arms two pan balance and need to weigh objects with integral weights
in the range 1 to 40 kilo grams. We have a set of standard weights and can place the
weights in any pan. . (i.e) some weights can be in a pan with objects and some weights
can be in the other pan. The minimum number of standard weights required is:
a. 4
b. 10
c. 5
d. 621. A white cube(with six faces) is painted red on two different faces. How many different
ways can this be done (two paintings are considered same if on a suitable rotation of the
cube one painting can be carried to the other)?
a. 2
b. 15
c. 4
d. 30
22. How many divisors (including 1, but excluding 1000) are there for the number 1000?
a. 15
b. 16
c. 31
d. 10
23. In the polynomial f(x) =2*x^4 - 49*x^2 +54, what is the product of the roots, and what is
the sum of the roots (Note that x^n denotes the x raised to the power n, or x multiplied
by itself n times)?
a. 27,0
b. 54,2
c. 49/2,54
d. 49,27
24. In the polynomial f(x) = x^5 + a*x^3 + b*x^4 +c*x + d, all coefficients a, b, c, d are integers.
If 3 + sqrt(7) is a root, which of the following must be also a root?(Note that x^n denotes
the x raised to the power n, or x multiplied by itself n times. Also sqrt(u) denotes the
square root of u, or the number which when multiplied by itself, gives the number u)?
a. 3-sqrt(7)
b. 3+sqrt(21)
c. 5
d. sqrt(7) + sqrt(3)