DIRECTIONS for the questions 1 to 5 : Study the given information carefully to answer the given question:
A boat takes a total time of twelve hours to travel 105 kms upstream and the same distance downstream. The speed of the boat in still water is six times of the speed of the current. What is the speed of the boat in still water? (In km/hr)
12
30
18
24
36
Answer : Option C.
Let ‘x’ be the speed of Boat in still water, and ‘y’ be the speed of current.
Then, according to the question,
Speed of the boat in still water = 6 speed of current
x = 6y
Also given that ,
105/(x+y) +105/(x-y) =12
105/7y +105/5y =12
12y=36
y=3
Therefore, x= 6×3=18
Speed of the boat in still water= 18kmph
The respective ratio between numbers of bags available in store P in August and that available in the same storein July was 5: 4. How many bags were available in store P in August as compared to July?
150
90
24
60
45
Answer : Option A.
Number of bags available in P store in July = 20% of 600 = 120.
Now, since we have
Number of bags available in store P in August : Number of bags available in P store in July = 5:4
=> P : 120 = 5 : 4
Thus, number of bags available in Store P (In August) = (5/4)x120 = 150
In September, the total number of bags available in all the stores together was 90 more than that available in July, What was the percent increase in the total number of bags available in all the stores together from July to September?
10
12
20
18
15
Answer : Option E.
According to the question, Total number of bags available in September = 600+90= 690
% change =690-600/600 ×100=90/6 = 15
In July, 4/15 of the available bags in store Q remained unsold and 5/12 of the available bags in store S remain unsold. How many bags were sold by stores Q and S together in July?
159
146
154
168
163
Answer : Option A.
Bags sold by store Q = (1- 4/15) of 25% of 600 = 11/15 of 25% of 600 = 110
And bags sold by store S = (1- 5/12) of 14% of 600 = 7/12 of 14% of 600 = 49
Thus, total bags sold by stores Q and S together in July = 159
Two years ago, the respective ratio between A's age at that time and B's age at that time was 5:9. A's age three years ago was 13 years less than B's age six years ago. What is B's present age?
38 years
30 years
34 years
32 years
36 years
Answer : Option A.
Two year ago, ratio between A’s age and B’s age at that time = 5:9
It means A’s age at that time = 5X, B’s age at that time = 9X
A’s age 3 year ago = 5X - 1, B’s age 6 years ago = 9X - 4
As given in question, 9X – 4 – (5X - 1) = 13
Solving, we get X = 4
Thus, B’s Present age = 9X+2 = 9×4+2 = 38 years
A box contains 2 white, 3 black and 4 red balls. In how many ways can three balls be drawn from the box, if at least one black ball is to be included in the draw?
64
32
48
96
None of these
Answer : Option A.
Reqd. number of ways =( Total of 3 from 9)-( Total of 3 from 6 non black)=9C3–6C3 = 84 – 20 = 64
There are 3 vacancies in a firm and 15 applicants. Find the total number of ways of filling these vacancies.
3375
2730
560
600
None of these
Answer : Option B.
Reqd. number of ways = 15 × 14 × 13 = 2730
There is a natural number which becomes equal to the square of a natural number when 100 is added to it, and to the square of another natural number when 168 is added to it. Find the number.
189
69
156
224
None of these
Answer : Option C.
Try by options. 3rd option is correct because 100 + 156 = 256 (square of 16) and 168 + 156 =
324 (square of 18).
No other option is satisfying the 2nd condition.
In a rectangular auditorium, chairs are arranged in rows and columns. The number of chairs in each column is more than the number of chairs in each row by 5. If there are in all 300 chairs, find the number of chairs in each row and in each column.
25,20
30,10
23,18
None of these
Answer : Option D.
Go by options. When there were 300 chairs, so product of chairs in rows and chairs in columns
should be 300.
Difference of 5 should be there between the seats in rows and columns.
So no option out of 1st 3
is satisfying the conditions. So answer is 4th option and correct values are 20 and 15.
