1. The ratio of the ages of the father and the daughter at present is 3:1. Four years ago the ratio was 4:1. The average age of the father and daughter 2 years hence will be:
a. 24
b. 26
c. 25
d. 36
2. Jugni started her journey from Lucknow to Kolkata, which is 200km, at the speed of 40kmph then she went to Bangalore which is 300km, at the speed of 20kmph. Further she went to Ahmedabad which is 500km, at the speed of 10kmph. The average speed of Jugni is :
a. 14 2/7 kmph
b. 14 5/7 kmph
c. 15.6 kmph
d. None of these
3. Sagar went to a post-office at the speed of 60 kmph while returning for his home he covered the half of the distance at speed of 10 kmph, but suddenly he realized that he was getting late so he increased his speed and reached the home by covering rest half of the distance at the speed of 30 kmph. The average speed of the Sagar in the whole journey is:
a. 5.67 kmph
b. 24 kmph
c. 22.88 kmph
d. 5.45 kmph
4. The average age of 9 numbers is 11. If each of these 9 numbers is multiplied by 5 and then 5 is added to each of theese resultant numbers, then the new average is:
a. 20
b. 30
c. 60
d. 50
5. The average score of Dhoni after 48 innings is 48 and in the 49th innings Dhoni scores 97 runs. In the 50th innings the minimum number of runs required to increase his average score by 2 than it was before 50th innings:
a. 99
b. 149
c. 151
d. can't be determined
# Answers
1.Sol: Let the present age of father be 3xand daughter be x.
So, the 4 years ago father's age and daughter's age was (3x - 4) and (x - 4).
Therefore, (3x-4)/(x-4) = 4/1
-->> x = 12 years and 3x = 36 years
Hence, the present average age of father and daughter = 24
After 2 years, their average age will be = 24+2 = 26 years
2.Sol: Average speed = Total distance / Total time
-->> (200 + 300 + 500) / (200/40 + 300/20 + 500/10)
-->> 1000/70 = 100/7 = 14 2/7 kmph
3. Sol: Average speed when Sagar was returning
-->> 2*10*30/40 = 15 kmph
Now, the average speed during the whole journey is
-->> 2*15*60/75 = 24 kmph
4. Sol: New average = 11*5 + 5 = 60
5. Sol: The average score after 48th innings = 48
The average score after 49th innings = 49
Since (48*48 + 97)/49 = 49
Now the requirement of runs = 49 + (50*2) = 149
or (50*51) - (49*49) = 149
a. 24
b. 26
c. 25
d. 36
2. Jugni started her journey from Lucknow to Kolkata, which is 200km, at the speed of 40kmph then she went to Bangalore which is 300km, at the speed of 20kmph. Further she went to Ahmedabad which is 500km, at the speed of 10kmph. The average speed of Jugni is :
a. 14 2/7 kmph
b. 14 5/7 kmph
c. 15.6 kmph
d. None of these
3. Sagar went to a post-office at the speed of 60 kmph while returning for his home he covered the half of the distance at speed of 10 kmph, but suddenly he realized that he was getting late so he increased his speed and reached the home by covering rest half of the distance at the speed of 30 kmph. The average speed of the Sagar in the whole journey is:
a. 5.67 kmph
b. 24 kmph
c. 22.88 kmph
d. 5.45 kmph
4. The average age of 9 numbers is 11. If each of these 9 numbers is multiplied by 5 and then 5 is added to each of theese resultant numbers, then the new average is:
a. 20
b. 30
c. 60
d. 50
5. The average score of Dhoni after 48 innings is 48 and in the 49th innings Dhoni scores 97 runs. In the 50th innings the minimum number of runs required to increase his average score by 2 than it was before 50th innings:
a. 99
b. 149
c. 151
d. can't be determined
# Answers
1.Sol: Let the present age of father be 3xand daughter be x.
So, the 4 years ago father's age and daughter's age was (3x - 4) and (x - 4).
Therefore, (3x-4)/(x-4) = 4/1
-->> x = 12 years and 3x = 36 years
Hence, the present average age of father and daughter = 24
After 2 years, their average age will be = 24+2 = 26 years
2.Sol: Average speed = Total distance / Total time
-->> (200 + 300 + 500) / (200/40 + 300/20 + 500/10)
-->> 1000/70 = 100/7 = 14 2/7 kmph
3. Sol: Average speed when Sagar was returning
-->> 2*10*30/40 = 15 kmph
Now, the average speed during the whole journey is
-->> 2*15*60/75 = 24 kmph
4. Sol: New average = 11*5 + 5 = 60
5. Sol: The average score after 48th innings = 48
The average score after 49th innings = 49
Since (48*48 + 97)/49 = 49
Now the requirement of runs = 49 + (50*2) = 149
or (50*51) - (49*49) = 149
No comments:
Post a Comment
Note: only a member of this blog may post a comment.