Latest Elitmus Aptitude Question SOLUTION: a boll drop from a height 40 m then it come to ground and again jump its half of back height then till it come to rest how it cover the distance from start point to its rest time..

• Placement Papers
• /
• Elitmus
• /
• Numerical Ability
• /
• Arithmetic

Elitmus Question Papers:

(#M40155402) ELITMUS Numerical Ability question quantative aptitude Keep an EYE

a boll drop from a height 40 m then it come to ground and again jump its half of back height then till it come to rest how it cover the distance from start point to its rest time..

optns nt remember

Asked In Elitmus kuldeep kumar (8 years ago)

Solved kundan verma Read Solution (7)

Is this Puzzle helpful?   (11)   (1) Submit Your Solution Arithmetic

Read Solution (7) :

kundan verma  (8 years ago) Best Solution

Gp series question.... when ball first rebounce then its distance 4om and then in 2nd rebounce half of 40 and its jump upside first and then go belowside so its distance 40(1/2)*2. and in third time rebounce 40(1/2)^2*2 and so on....
it's gp series becomes ....40+40(1/2)*2+40(1/2)^2*2+40(1/2)^3*2+........
40+2{ 40(1/2) + 40(1/2)^2 + 40(1/2)^3 +......+infinite term.}
here a=40(1/2) and r=1/2
Sum of infinite GP series =a/(1-r) = 40*(1/2) /1-(1/2)=40.
so 40+2*40=120 ans

Is this solution Helpfull? Yes (35) | No (1)  

Ashutosh  (8 years ago)

Its a G.P ques......a/(1-r)

where a=40 and r=1/2. So 40/(1- 0.5) + 20/(1-0.5)= 80+40= 120

Is this solution Helpfull? Yes (9) | No (1)  

Anurag Bhardwaj  (8 years ago)

S1=40+40(1/2)*2+40(1/2)^2*2+........
S2=40+2{ 40(1/2) + 40(1/2)^2 + 40(1/2)^3 +......+infinite term.}
here a=40(1/2) and r=1/2
Sum of infinite GP series S2=a/(1-r) = 40*(1/2) /1-(1/2)=40.
S1=80
so 40+2*40=120

Is this solution Helpfull? Yes (2) | No   

rajesh  (8 years ago)

40+20+20=80

Is this solution Helpfull? Yes (1) | No (5)  

mcamanjeet  (8 years ago)

Gp series question.... when ball first rebounce then its distance 4o m and then in 2nd rebounce half of 40 and its jump upside first and then go belowside so its distance becomes two times of half of 40 that is 40(1/2)*2. and similarly in third time rebounce 40(1/2)^2*2 and so on....
it's G.P series becomes 40 + 40(1/2)*2 + 40(1/2)^2*2 + 40(1/2)^3*2 + ........
40 + 2 { 40(1/2) + 40(1/2)^2 + 40(1/2)^3 +......+infinite term.}
40 + 2 * 40 { 1/2 + 1/2^2 + 1/2^3+1/2^4......+infinite term.}
here a = 1/2 and r=1/2
=40 + 80 ( 1/2/1-1/2) ( sum of infinite terms of G.P series is a/1-r ) [ a=1/2 and 1-r = 1-1/2=1/2 ]
=40+80
ans =120

Is this solution Helpfull? Yes (1) | No   

Amit Kumar  (8 years ago)

80m= 40+20+20

Is this solution Helpfull? Yes | No (1)  

Ayushi Baharani  (8 years ago)

The distance covered for the 1st time the ball goes up n come down is 40+40=80
the second time it goes upto half of 40 i.e. 20, but total dis now covered is 20+2==40 (both going up n back down)
so the series is like 80,40,20,10.......n so on
so, on applying G.P, a/(1-r) where a=80 n r=1/2 ,
the ans is 160

Is this solution Helpfull? Yes | No   

Please Login to Read Solution.