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Maths Puzzle
In covering a distance of 30 km, Abhay takes 2 hours more than Sameer. If Abhay doubles his speed, then he would take 1 hour less than Sameer. Abhay's speed is:
A. 5 kmph B. 6 kmph
C. 6.25 kmph D. 7.5 kmph
Read Solution (Total 6)
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- Let Time taken by Sameer=X hr ,D=30km ,S=D/T
When Abhay speed is S then S=(30/(X+2))(coz abhay takes 2 hrs more than Sameer)--1
When abhay speed is doubled i,e 2S then 2S=(30/(X-1))(coz abhay takes 1 hr less than Sameer)--2 Now divide eq1/eq2 then X=4Hrs
Now substitute X in eq 2 we get S=5Kmph
- 11 years agoHelpfull: Yes(12) No(0)
- A.5 Kmph
Abhay's Speed=5 Kmph & Sameer's Speed=7.5 Kmph
According to condition Time taken for Abhay=30/5=6 Hrs. & for Sameer=30/7.5=4 Hrs.
If Abhay doubles the speed,then time taken=30/10=3 Hrs.which is less than 1 Hr. by Sameer. - 12 years agoHelpfull: Yes(7) No(7)
- Let Abhay's speed be x km/hr
and sameer's speed be y km/hr
Abhay takes 2 hours more than Sameer
i.e (30/x)-(30/y)=2 ........ I
Abhay doubles his speed, i.e his speed becomes 2x
then he would take 1 hour less than Sameer
i.e (30/y)-(30/2x)=1......... II
ADD I and II
you will get
(30/x)-(30/2x)=3.......... III
solve III you will get x=5 km/h - 10 years agoHelpfull: Yes(7) No(0)
- let abhay' speed = x km/hr
then, 30/x-30/2x=3
6x=30
x=5 km/hr - 11 years agoHelpfull: Yes(1) No(5)
- suppose time taken by Sameer=x,
then time taken by Abhay =x+2;
according to question
s=d/t
s=30/x+2...........(1)
2s=30/x-2..........(2)
now divide eq1/eq2
1/2=x-1/x+2
x=4
put the value of x in equ 1
s=30/6
s=5kmp/h
- 9 years agoHelpfull: Yes(1) No(1)
- let time taken by Sameer be x i.e. time taken by Abhay will be x+2
since the distance travelled is 30km,
Abhay's speed is 30/(x+2)
if Abhay doubles his speed then he would take an hour less to complete the same distance than Sameer
i.e.
2(30/(x+2)) is the doubled speed of Abhay
30/2(30/(x+2)) will be the time taken by him
we know that time taken by Sameer is "x"
but Sameer takes and hour longer than Abhay
on equating this...
(x+2)/2=x-1
therefore on solving the above equation
x=4 i.e.
time taken by Abhay is 4+2=6 hours
hence his speed will be = 30/6=5
Abhay's speed is 5kmph - 4 years agoHelpfull: Yes(0) No(0)
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