Cocubes Computer Fundamentals Questions And Answers
Cocubes Computer Fundamentals MCQs : This section focuses on "Computer Fundamentals" of Cocubes Exam. These Multiple Choice Questions (MCQ) should be practiced to prepare for Cocubes Exam, entrance exams and other competitive examinations.
1. A, B and C can all together do piece of work in 20 days, in which B takes twice as long as A and C together do the work and C takes twice as long as A and B together take to do the work. In how many days B can alone do the work?
A. 40
B. 35
C. 60
D. 45
View Answer
Ans : C
Explanation: (A+C) in x days so B completes in 2x days then (1/x) + (1/2x) = 1/20
solve, x = 30, so B 2x = 60days
2. The cost price of item B is Rs. 200/- more than the cost price of item A. Item A was sold at a profit of 20% and item B was sold at a loss of 30%. If the respective ratio of selling prices of items A and B is 6 :7, what is the cost price of item B?
A. Rs. 520
B. Rs. 400
C. Rs. 430
D. Rs. 360
View Answer
Ans : B
Explanation: Let the CP of item A be x, CP of item B is x+200.
(120/100*x)/(x+200)*70/100 = 6/7
120x/(x+200)*70=6/7
20x/10(x+200) = 1
X=Rs. 200. CP of item B is 200+200 = Rs. 400.
3. If A =x% of y and B =y%of x, then which of the following is true?
A. A is equal to B
B. A is smaller than B
C. A relationship between A and B cannot be determined
D. If x is greater than y, then A is less than B
View Answer
Ans : A
Explanation: A=(x/100)*y=xy/100
B=(y/100)*x=xy/100
Therefore A=B
4. What is the largest 3 digit number exactly divisible by 18?
A. 978
B. 954
C. 980
D. 990
View Answer
Ans : D
Explanation: Largest 3 digit number = 999
999 ÷ 18 = 55, remainder = 9
Hence largest 3 digit number exactly divisible by 18
= 999 - 9 = 990
5. A vessel contains 180 litres of mixture of milk and water in the respective ratio of 13 : 5. Fifty-four litres of this mixture was taken out and replaced with 6 litres of water, what is the approximate percentage of water in the resultant mixture?
A. 41
B. 31
C. 24
D. 9
View Answer
Ans : B
Explanation: Milk: water = 13:5
Volume of solution=180
Solution taken out= 54
Volume of solution left= 180-54=126
In 126 l solution,
Milk= 126*13/18= 91
Water=126*5/18=35
As 6 l water is added
Water= 35+6= 41
Total solution volume= 126+6= 132
Percentage of water= 41/132*100= 31%
6. The HCF and LCM of two num¬bers are 12 and 924 respectively. Then the number of such pairs is
A. 0
B. 1
C. 2
D. 3
View Answer
Ans : A
Explanation: Let the numbers be 12x and 12y where x and y are prime to each other.
∴ LCM = 12xy
∴ 12xy = 924
⇒ xy = 77
∴ Possible pairs = (1, 77) and (7,11)
7. The ages of the two persons differ by 20 years. If 5 year ago, the older one be 5 times as old as the younger one, then their present ages, in year are:
A. 24, 4
B. 30, 10
C. 20, 10
D. 15, 45
View Answer
Ans : B
Explanation: Let the age be x and y years now.
Then, x−y=20 -------- (i)
and (x−5)=5(y−5) ------- (ii)
On solving both equation we get:
x=30 and y=10
8. What will be unit’s digit in the result of the expression
3^69 * 7^71 * 9^5?
A. 6
B. 4
C. 1
D. 7
View Answer
Ans : C
Explanation: Unit digit in 3^4 = 1
Unit digit in (3^4)^17 = 1
Unit digit in 3^(69)
= Unit digit in [ (3^4)^17 x 3 ] = (1 x 3) = 3
Unit digit in 7^4
= Unit digit in (7^4)^17 is 1.
Unit digit in 7^(71)
= Unit digit in [(7^4)^17 x 7^3] = (1 x 3) = 3
Unit digit in 9^5 = 9
Required digit = Unit digit in (3 x 3 x 8) = 1
9. The ratio of the volumes of two cubes is 729: 1331. What is the ratio of their total surface areas?
A. 81 : 121
B. 729 : 1331
C. 0.384027777777778
D. 27 : 121
View Answer
Ans : A
Explanation: Ratio of the sides = ³√729 : ³√1331 = 9 : 11
Ratio of surface areas = 9^2 : 11^2 = 81 : 121
10. Find the Value of tan60° + tan120°?
A. half
B. one
C. one-third
D. zero
View Answer
Ans : D
Explanation: tan(60) + tan(180-120)
=tan(60)+(-tan(60)) [because in second quadrant tan is -ve]
=0
Discussion