Tuesday, October 6, 2015

Cocubes Quantitative Aptitude Questions-1

Quantitative Aptitude For Competitive Examinations (English) 7th Edition
1. The cost price of 10 articles is equal to the selling price of 9 articles. find the profit percent.
a. 101/9 %           b. 100/9 %           c. 102/9 %            d. 103/9 %
Ans: 100/9 %
Let Cost Price be x and selling price be y
Then given that cost price of 10 articles is equal to the selling price of 9 articles
That means 10x=9y
Y= 10x/9
Profit percent = (( selling price – cost price )/cost price ) * 100
= 100/9 %


2. The ratio of radii of two right circular cylinders is 6:7 and their heights are in the ratio 5:9. The ratio of their respective curved surface areas is                  a. 14:15                 b. 17:19                c. 23:29                 d. 10:21
Ans: 10 : 21
Curved surface area of a cylinder = 2 * Pi * r * h
Ratio = (6/7) * (5/9) = 10:21

3. In how many ways can the 7 letters A,B,C,D,E,F and G be arranged so that C and E never together.
a. 5040                  b. 6480                  c. 3600                  d. 1440
Ans: 3600
C and E never together = Total arrangements – C and E together
Total arrangements are 7!
C and E together = pack  c and e into one unit + 5 other alphabets = 6! 2! ( 2! Is two arrange c and e internally)
C and E never together = Total arrangements – C and E together = 7! – 6! 2! = 3600

4. How many numbers are there in all from 4000 to 4999 (both 4000 and 4999 included) having at least one of their digits repeated?           a. 356                    b. 216                    c. 496                     d. 504
Ans:  496
Atleast one of their digits repeated = Total numbers – None of the digits repeated
Total numbers from 4000 to 4999 = 1000
None of the digits repeated =  _ _ _ _
There are total 4 places
1st place is filled with 4 only. So only one choice
2nd place is filled with any 9 digits except 4 as we have used 4 in 1st place. So 9 choices
Similarly 3rd place is filled with any 8 digits. So we have 8 choices
4th place is filled with any 7 digits. So we have 7 choices.
So total arrangements = 1 * 9 * 8 * 7 = 504
Ans= 1000 – 504 = 496

5. if 1/2x +1/4x+1/8x=14  Then the value of x is:                 a. 8         b. 12      c. 4         d. 16

Ans: x = 16


8. Find the value of  h[f(1,2,3), g(2,1,-2), h(1,-1,-1)].         a. 0.5                     b. none                                c. 1                         d. 0
Ans(D)

9. A trapezium with an area of 5100 cm2 has the perpendicular distance between the two parallel sides of 60m . if one of the parallel sides be 40m. find the legth of the other side.
a. 130 m               b. 110 m               c. 120 m                d. 145 m
Ans:  130 m
Area of a trapezium = (1/2) (a+b) h

10. Find the simple interest on Rs. 306.25 from March 3rd to July 27th( In the same year ) at 3.75 percent.
a. Rs. 4.57            b.  Rs. 4.59           c. Rs. 4.53            d. Rs 4.58
Ans: 4.59
from March 3rd to July 27th( In the same year) = 146 days
(306.25 * 146 * 3.75 )/ ( 365 * 100) = 4.59

11. Dhruv and Naksh drive at the speeds of 36 Kmph and 54 kmph respectively. If Naksh takes 3 hours lesser than what dhruv takes for the same distance. Then distance is :      a. 324 km   b. 524 km       c. 320 km             d. 420 km
Ans:  324 km
Let dhruv takes t hours then naksh takes t-3 hours
Because distance is same in both cases
So 36 * t = 54 (t-3)
t=9
ans: 36 * 9 = 324 km

12. The radius of wheel of axis's car is 50 cm. What is the distance that the car would cover in 14 revolutions?
a. 11 m                  b. 22 m                 c. 33 m                  d. 44 m
Ans: 44 m
Distance covered in one revolution is equal to wheel surface area = 2 * Pi * r
Distance covered in 14 revolutions = 14 ( 2 * (22/7) * 50) = 44000 cm= 44 m


13.  P can do a piece of work in 5 days of 8 hours each and Q can do in 4 days of 6 hours each. How long will they take do it working  5 hours a day? a. 2 days               b. 3 days              c. 4 days               d. 5 days
Ans:  3 days
P can do in 5* 8 hours= 40 hours
Q can do in = 24 hours
Working together in one hour = (1/40) + (1/24) = 1/15
Total work can be finished in 15 hours
They 5 hours a day so total number of days = 15/5 = 3 days

14. Libra had three diamond weighing equal. One of the diamond fell and broke into 4 equal pieces weighing 20gm each. what was the total weight of three diamonds.
a. 200 gm             b. 280 gm             c. 320 gm             d. 240 gm
Ans: 20 * 4 * 3 = 240 gm

16. if the antecedent and consequent of a ratio are increased by 5 and 6 respectively then the ratio is 5:6. find the original ratio.     a. 5:6                     b. 1:2                     c. 2:3                      d. 3:4
Ans: let’s say original ratio is x:y
(x+5)/(y+6) = 5/6
Then x/y = 5/6

17. Rohit and rahul start from the same point and move away from each other at right angle. After 4 hours they are 80 km apart. if the speed of rohit is 4 kmph more than rahul. what is the speed of rohit?
a. 16 kmph          b. 20 kmph          c. 12 kmph          d. none
Ans:  x is the speed of rahul then (x+4) will be rohit speed


802 = (4x)2 + ((x+4)4)2
X=12
Rohit speed = 12 + 4 = 16kmph

18. abhimanyu and supreet can together finish a work in 50 days. They worked together for 35 days and then supreet left. After another 21 days, abhimanyu finished the remaining  work. In how many days abhimanyu alone can finish the work?                a. 70 days            b. 75 days            c. 80 days             d. 60 days
Ans: 35 days worked together +  21 days abhimayu worked = finished the work
35(1/50) + 21(x) = 1
X=70 days

19. if two fair dice are thrown simultaneously. then what is the probability that sum of the numbers appearing on the top faces of the dice is less than 4?  a. 6/14                  b. none                                c. 1/12                   d. 3/18
Ans:  possible cases are (1,1) (1,2) and (2,1) = 3


3/36 = 1/12

20.

which of the following equations best describes the given curve?
a. (y+3) = x          b. y= cos x           c. y = tan x           d. (x+y) = 0

Ans: (D)