A green lizard can travel from the green cave to the blue cave in 108

Question

A green lizard can travel from the green cave to the blue cave in 108 minutes; the blue lizard can travel from the blue cave to the green cave in 25% less time. If the green lizard started to travel 7.5 minutes before the blue lizard, how many minutes after the blue lizard, will the green lizard pass the middle line?

A. 2.
B. 3.5.
C. 4.
D. 5.5.
E. 6.

A. 2.
B. 3.5.
C. 4.
D. 5.5.
E. 6.

LightYagami · Answer

Time take by the green lizard to cover the distance between the caves = 108 mins

Time take by the green lizard to cover half the distance = 108/2 = 54 mins

Time take by the blue lizard to cover the distance between the caves = 108 x 3/4 =81 mins

Time take by the blue lizard to cover half the distance = 81/2 = 40.5 mins

Now the green lizard had been travelling for 7.5 mins when the blue lizard started. Therefore when the blue lizard starts to move the green lizard will have to cover 54 - 7.5 = 46.5 mins worth of distance at its current speed.

Difference in time when they both reach the mid point = 46.5 - 40.5 = 6mins.

E IS THE CORRECT ANSWER.

sharma123 · Answer

time taken by green lizard to cover half dist=54 min
time taken by blue lizard to cover full distance =0.75*108=81
time taken by blue lizard to cover half dist=40.5
As green lizard started early it will reach 54-7.5=46.5
So extra time taken by green lizard is 46.5-40.5=6mins

adiagr · Answer

Blue Lizard takes 25 % less time. 25 % of 108 = 27 minute. 108-27 = 81 minutes.

Let the distance between two caves is D.

Then Speed of Green Lizard : (D/108) 
 Speed of Blue Lizard : (D/81)

To reach mid point Blue lizard will take (D/2)/ (D/81) = 40.5 minutes.

To reach mid point Green lizard will take (D/2)/ (D/108) = 54 minutes

If the two lizards start movement at the same time, then Green lizard will reach mid point 54-40.5 = 13.5 minutes later than Blue lizard.

Now this green lizard actually moves 7.5 minute earlier than Blue lizard.

So it will be late only by 13.5 - 7.5 = 6 minutes.

E is the answer.

Divyadisha · Answer

Time taken by green lizard to reach middle of the cave= 108/2= 54 mins

Time taken by blue lizard to reach middle of the cave= 108*75/100*1/2= 40.5

Time difference between two without any condition= 54-40.5= 13.5

But, green lizard started 7.5 ins earlier, so the actual time difference= 13.5- 7.5= 6 mins

E is the answer

bumpbot · Answer

Automated notice from GMAT Club BumpBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

A green lizard can travel from the green cave to the blue cave in 108

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Problem Solving (PS) Questions

A green lizard can travel from the green cave to the blue cave in 108

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards