1080.A bag contains 2 yellow, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?
1/2
10/21
9/11
7/11
Explanation:
Total number of balls = 2 + 3 + 2 = 7
Let S be the sample space.
n(S) = Total number of ways of drawing 2 balls out of 7 = 7C2
Let E = Event of drawing 2 balls , none of them is blue.
n(E) = Number of ways of drawing 2 balls , none of them is blue
= Number of ways of drawing 2 balls from the total 5 (=7-2) balls
= 5C2
Therefore,there are two blue balls in the total 7 balls. Total number of non-blue balls = 7 - 2 = 5)
P(E) = n(E)/n(S)=5C2/7C2=(5×42×1)/(7×62×1)=5×4/7×6=10/21
Total number of balls = 2 + 3 + 2 = 7
Let S be the sample space.
n(S) = Total number of ways of drawing 2 balls out of 7 = 7C2
Let E = Event of drawing 2 balls , none of them is blue.
n(E) = Number of ways of drawing 2 balls , none of them is blue
= Number of ways of drawing 2 balls from the total 5 (=7-2) balls
= 5C2
Therefore,there are two blue balls in the total 7 balls. Total number of non-blue balls = 7 - 2 = 5)
P(E) = n(E)/n(S)=5C2/7C2=(5×42×1)/(7×62×1)=5×4/7×6=10/21
1081.One year ago Jaya was four times as old as her daughter Nikitha. Six years hence, Mrs.Jayas age will exceed her daughters age by 9 years. The ratio of the present ages of Jaya and her daughter is :
9 : 2
11: 3
12: 5
13: 4
Explanation:
Let Nikithas age 1 year ago = x
Then Jayas age 1 year ago = 4x
After 6 years their ages are 4x+7, x+7
(4x+7) - (x+7) = 9 or x = 3
Present age of Jaya = (12+1) years = 13 years
Present age of Nikitha = (3+1) years = 4 years
Ratio of their ages = 13 : 4
Let Nikithas age 1 year ago = x
Then Jayas age 1 year ago = 4x
After 6 years their ages are 4x+7, x+7
(4x+7) - (x+7) = 9 or x = 3
Present age of Jaya = (12+1) years = 13 years
Present age of Nikitha = (3+1) years = 4 years
Ratio of their ages = 13 : 4
1082.Five years ago, the total of the ages of a father and his son was 40 years. The ratio of their present ages is 4 : 1. What is the present age of the father?
30 years
20 years
25 years
None of these
Explanation:
Let sons age = x. Then fathers age = 4x
(x-5)+(4x-5)=40 ⇒⇒ x = 10
Present age of father = 40 years
Let sons age = x. Then fathers age = 4x
(x-5)+(4x-5)=40 ⇒⇒ x = 10
Present age of father = 40 years
1083.A father is twice as old as his son. 20 years ago the age of the father was 12 times the age of the son. The present age of the father is:
44 years
32 years
22 years
45 years
Explanation:
Let sons age = x. Then, fathers age = 2x.
12(x-20)=(2x-20)⇒⇒x=22
Fathers present age = 44 years
Let sons age = x. Then, fathers age = 2x.
12(x-20)=(2x-20)⇒⇒x=22
Fathers present age = 44 years
1084.The total age of A and B is 12 years more than the total age of B and C. C is how many years younger than A ?
12 years
13 years
14 years
15 years
Explanation:
(A+B) - (B+C) = 12
A - C = 12.
C is younger than A by 12 years.
(A+B) - (B+C) = 12
A - C = 12.
C is younger than A by 12 years.
1085.A persons present age is two-fifth of the age of his mother. After 8 years, he will be one-half of the age of his mother. How old is the mother at present
38
40
42
44
Explanation:
Let the mothers present age be x years.
Then, the persons present age = years.
2(2x + 40) = 5(x + 8)
x = 40
Let the mothers present age be x years.
Then, the persons present age = years.
2(2x + 40) = 5(x + 8)
x = 40
1086.A father said his son , " I was as old as you are at present at the time of your birth. " If the father age is 38 now, the son age 5 years back was :
14 Years
19 Years
33 Years
38 Years
Explanation:
Let the sons present age be x years .Then, (38 - x) = x x= 19.
Sons age 5 years back = (19 - 5) = 14 years
Let the sons present age be x years .Then, (38 - x) = x x= 19.
Sons age 5 years back = (19 - 5) = 14 years
1087.Sachin is younger than Rahul by 7 years. If the ratio of their ages is 7:9, find the age of Sachin
24.5
25.5
26.5
27.5
Explanation:
If Rahul age is x, then Sachin age is x - 7,
so,
9x - 63 = 7x
2x = 63
x = 31.5
So Sachin age is 31.5 - 7 = 24.5
If Rahul age is x, then Sachin age is x - 7,
so,
9x - 63 = 7x
2x = 63
x = 31.5
So Sachin age is 31.5 - 7 = 24.5
1088.The ratio of the ages of father and son at present is 6:1. After 5 years the ratio of will become 7:2. The present age of the son is :
5 years
6 years
9 years
10 years
Explanation:
6x+5 / x+5=7 / 2
⇒2(6x+5)=7(x+5)
⇒x=5
Sons present age = 5 years
6x+5 / x+5=7 / 2
⇒2(6x+5)=7(x+5)
⇒x=5
Sons present age = 5 years
1089.10 years ago, Chandravatis mother was 4 times older than her daughter. After 10 years, the mother will be twice older than the daughter. The present age of Chandravati is:
5 years
10 years
20 years
30 years
Explanation:
Let Chandravatis age 10 years ago be x years.
Mothers age 10 years ago =(4x) years
2(x+20)=(4x+20)⇒⇒ x = 10
Present age of Chandravathi = (x+10)=20 years
Let Chandravatis age 10 years ago be x years.
Mothers age 10 years ago =(4x) years
2(x+20)=(4x+20)⇒⇒ x = 10
Present age of Chandravathi = (x+10)=20 years
1090.The age of Arvinds father is 4 times his age. If 5 years ago, fathers age was 7 times the age of his son at the time, what is Arvinds fathers present age?
35 years
40 years
70 years
84 years
Explanation:
Let Arvinds age be x years
Then his fathers age = 4 x years
(4x-5)=7(x-5) or 3x = 30 or x = 10
Hence Arvinds fathers age is 40 years
Let Arvinds age be x years
Then his fathers age = 4 x years
(4x-5)=7(x-5) or 3x = 30 or x = 10
Hence Arvinds fathers age is 40 years
1091.Pushpa is twice as old as Rita was two years ago. If the difference between their ages is 2 years, how old is Pushpa today?
6 years
8 years
10 years
12 years
Explanation:
Let Ritas age 2 years ago be x years. Pushpas present age = (2x) years.
2x-(x+2)=2 ⇒⇒ x = 4
Pushpas present age = 8 years
Let Ritas age 2 years ago be x years. Pushpas present age = (2x) years.
2x-(x+2)=2 ⇒⇒ x = 4
Pushpas present age = 8 years
1092.The sum of the ages of a father and son is 45 years. Five years ago the product of their ages was 4 times the fathers age at that time. The present ages of the father and son, respectively are,
25 years, 10 years
36 years, 9 years
39 years, 5 years
none of these
Explanation:
Let the present ages of father and son be x years and (45-x) years
Then, (x-5)(45-x-5)=4(x-5)
45-x-5=4 or x = 36
The present ages of father and son are 36 years and 9 years respectively.
Let the present ages of father and son be x years and (45-x) years
Then, (x-5)(45-x-5)=4(x-5)
45-x-5=4 or x = 36
The present ages of father and son are 36 years and 9 years respectively.
1093.In 10 years, A will be twice as old as B was 10 years ago. If A is now 9 years older than B, the present age of B is:
19 years
29 years
39 years
49 years
Explanation:
Let the present ages of B and A be x years and (x+9) years respectively.
Then 10 years ago Bs age is (x - 10) and in the next 10 years As age is (x + 19)
Given that As age is twice of B
So (x + 19) = 2 x (x - 10) ⇒⇒ x + 19 = 2x - 20 ⇒⇒ x = 39
Let the present ages of B and A be x years and (x+9) years respectively.
Then 10 years ago Bs age is (x - 10) and in the next 10 years As age is (x + 19)
Given that As age is twice of B
So (x + 19) = 2 x (x - 10) ⇒⇒ x + 19 = 2x - 20 ⇒⇒ x = 39
1094.The sum of the ages of a son and father is 56 years. After 4 years, the age of the father will be three times that of the son. Their ages respectively are:
12 years, 44 years
16 years, 42 years
16 years, 48 years
18 years, 36 years
Explanation:
Let the present ages of son and father be x years
and (56-x) years respectively.
Then (56-x+4)=3(x+4)
or 4x =48 or x = 12
So their ages are 12 years, 44 years respectively.
Let the present ages of son and father be x years
and (56-x) years respectively.
Then (56-x+4)=3(x+4)
or 4x =48 or x = 12
So their ages are 12 years, 44 years respectively.
Express a speed of 36 Kmph in meters per second?
Solution:
• 36 * 5/18 = 10 mps
• 36 * 5/18 = 10 mps
The speed of a train is 90 Kmph. What is the distance covered by it in 10 minutes?
Solution:
90 * 10/60 = 15 kmph
90 * 10/60 = 15 kmph
In what time will a railway train 60 m long moving at the rate of 36 Kmph pass a telegraph post on its way?
Solution:
T = 60/36 * 18/5 = 6 sec
T = 60/36 * 18/5 = 6 sec
1223.The sum of the interior angles of a polygon is twice the sum of its exterior angles. How many sides does the polygon have?
8 sides
9 sides
12 sides
6 sides
1264.Two trains of equal length 120 metres move in the same direction. The faster train completely overtakes the slower one in 15 seconds. If the slower train were to move at half its speed, the over taking would take in 10 seconds. At what speeds are the 2 trains moving (faster and slower respectively in m/s)
28.5 kmph
none of these
24, 22
32, 16