By the time car A starts traveling car B has traveled 20 miles on a track that is 20Pi long i.e. circumference.
so to cover at the relative speed of 5 mph it will take (20pi - 12) / 5 = 4pi - 1.6 hrs.
What's the OA?
Hi sumit, ur approach is right but i think u missed important part. we need to find time by car B to travel when A has travelled 12 miles more than B. my approach would be: Again, using the speed formula, we can compute how long it will take them to meet up:
time to meet = 20(pi -1)/5 = 4 (pi -1) = 4pi -4 (this is after A starts in opposite direction by that time B has already travelled 10 hrs. Now, they are separating from each other a distance of 12 miles. The rate at which the two cars are separating is, again, the sum of their speeds. So:
time elapsed for them to separate 12 miles = 12/5 = 2.4 so total time travelled by car B = 10+ 4pi-4 + 2.4 = 4pi + 8.4 answer should be B. thanks for showing me the approach to consider circular motion problem. I was considering the usual straight line approach, which was wrong. :cheerio:
Here are my inputs:- Statement I: T=100.. So, R+S=80 and triangle is isosceles So, Just one option is left. R = S = 40
Statement II: S=40.. So, T+R=140 and triangle is isosceles Here we can have two options viz S=T or T=R:- a) If S=T, T = 40 and R = 100 b) If T = R, T = R = 70 So, we can't tell the soln. in case of statement 2. Hence, A should be the answer..
PGPEX_aspirant Says
No. Even in that case I do not agree with you. Even if ST is the base, then, I can conclude angle S and angle T to be equal, in that case, angle R can be (180-40-40 = 100), so I still feel, (d) is the correct answer. Does this makes sense?
I'm not clear abt the solu. Ques says that "if Jack picks a jellybean, he chooses one additional piece of candy and then stops. If he picks any non-jellybean candy, he stops picking immidietely.".........so, shouldn't it be: (J picks JB)*(J picks JB)*(R picks JB) + (J picks JB)*(J picks non JB)*(R picks JB) + (J picks non JB)*(R picks JB) ?
Can someone please clarify if I've misunderstood the problem? Thanks!
MissionPGPX Says
Yup, u got that right in the hole... perfect explanation...
hello puys... hope every1 doing great in GMAT prep. here is a nice one on probability... bit easy and wellknown from MGMAT...
Renne has a bag of candy. The bag has 1 candy bar, 2 lollipops, 3 jellybeans and 4 truffles. Jack takes one piece of candy out of the bag at random. If he picks a jellybean, he chooses one additional piece of candy and then stops. If he picks any non-jellybean candy, he stops picking immidietely. After jack picks his candy, renee will pick a piece of candy. what is the probability that Renee picks a Jellybean?
Its a PS and no options given. it has just 1 correct answer. will post OA soon. good luck!! :cheerio:
I'm not clear abt the solu. Ques says that "if Jack picks a jellybean, he chooses one additional piece of candy and then stops. If he picks any non-jellybean candy, he stops picking immidietely.".........so, shouldn't it be: (J picks JB)*(J picks JB)*(R picks JB) + (J picks JB)*(J picks non JB)*(R picks JB) + (J picks non JB)*(R picks JB) ?
Can someone please clarify if I've misunderstood the problem? Thanks!
hey, your approach is correct. i am extremely sorry for quoting previous response true, since i just looked at the answer and not detailed explanation. surprisingly answer with both approach is correct: 3/10
Below is a CAT question but looks similar to that in GMAT...
Bob and Charlie run a race between points P and Q,5 km apart.Bob starts at 6 a.m.from P at a speed of 5 km/hr,reaches Q,and returns to P at the same speed.Charlie starts at 6:45 a.m.from P at a speed of 10 km/hr,reaches Q and comes back to P at the same speed.(1) At what time do Bob and Charlie first meet each other (2) At what time does Charlie overtake Bob.
plz post your explanations and different approaches.
Below is a CAT question but looks similar to that in GMAT...
Bob and Charlie run a race between points P and Q,5 km apart.Bob starts at 6 a.m.from P at a speed of 5 km/hr,reaches Q,and returns to P at the same speed.Charlie starts at 6:45 a.m.from P at a speed of 10 km/hr,reaches Q and comes back to P at the same speed.(1) At what time do Bob and Charlie first meet each other (2) At what time does Charlie overtake Bob.
plz post your explanations and different approaches.
The Answer are 1: 7:10 am 2.7:30 am
below is the explanation: 1. Bob speed is 5km/hr so it will take 1hr (7:00 a.m.)to reach at P and Charlie starts at 6:45 with 10 Km/hr so at 7:00 am he has covered 2.5 km i.e. half of the distance. Now difference of distance between the Bob and Charlie is 2.5Km. and the relative speed is 10km +5km=15km as both are travelling in opposite direction . By speed distance formula time comes out to be 10min. Which should be added to 7:00am so net time is 7:10 am.
2. now Charlie reaches point P at 7:15 am and in these 15 minutes from 7:00 to 7:15 bob has travelled 5*(15/60)=1.25 km towards Q.U can again solve it with relative speed as bob and charlie are travelling in same direction now so relative speed is 10-5=5 km/hr and distance is 1.25 km again time comes out to be 15 min Another approach can be the ratio of speeds of two is in ratio 1:2 so if bob travels the distance in 1/2 hr charlie will cover up in 15 minutes.
WHAT IS THE REMAINDER WHEN 54 RAISE TO THE POWER 124 IS DIVIDED BY IS DIVIDED BY 17?
17*3 =51 so by remainder theorm 54 is reduced to 3
(3^154)/17 also 17*5=85 3^4=81
so reducing it further
3*3*(81^38 )/17 same by remainder theorm 81 can be reduced to -4 as power is even negative disappears so we are left with 9*(4^38 )/17 it can be written as 9*(16^19)/17 same by remainder theorm 9*(-1^19)/17 now we have odd power so we have a negative sign at the end -9/17
as remainder can't be negative so answer is 17-9=8
17*3 =51 so by remainder theorm 54 is reduced to 3
(3^154)/17 also 17*5=85 3^4=81
so reducing it further
3*3*(81^38 )/17 same by remainder theorm 81 can be reduced to -4 as power is even negative disappears so we are left with 9*(4^38 )/17 it can be written as 9*(16^19)/17 same by remainder theorm 9*(-1^19)/17 now we have odd power so we have a negative sign at the end -9/17
as remainder can't be negative so answer is 17-9=8
I hope this helps.:)
explanation is OK.power is taken 154 instead of 124... sahil bhai..sambhal ke.. my ans is 4..(process is same as explained above)
explanation is OK.power is taken 154 instead of 124... sahil bhai..sambhal ke.. my ans is 4..(process is same as explained above)
hey amyrocket, I also applied the same process but last step is different. 17*3 =51 so by remainder theorm 54 is reduced to 3
(3^124)/17 also 17*5=85 and 3^4=81
so reducing it further
(3^4)^31 / 17 = (81^31 )/17 same by remainder theorm 81 can be reduced to -4 as power is even negative disappears so we are left with (4^31 )/17 it can be written as 4*(16^15)/17 same by remainder theorm 4*(-1^15)/17
17*3 =51 so by remainder theorm 54 is reduced to 3
(3^124)/17 also 17*5=85 and 3^4=81
so reducing it further
(3^4)^31 / 17 = (81^31 )/17 same by remainder theorm 81 can be reduced to -4 as power is even negative disappears so we are left with (4^31 )/17 it can be written as 4*(16^15)/17 same by remainder theorm 4*(-1^15)/17 now we have odd power so we have a negative sign at the end -4/17
as remainder can't be negative so answer is 17-4=13 please explain the blue colored steps. are they correct?
There is a correction in one of your steps. it is in the following.
"Step1: (3^4)^31 / 17 = (81^31 )/17 same by remainder theorm 81 can be reduced to -4 as power is even negative disappears so we are left with Step2: (4^31 )/17"
It is not as you have mentioned it here as 31 is odd
Step2: is (-4)^31/17 which invariably becomes
(-1)(4^31)/17
The rest of the steps are as were mentioned by you. at the end it becomes 4 instead of -4.
A jar contains 30 marbles, of which 20 are red and 10 are blue. If 9 of the marbles are removed, how many of the marbles left in the jar are red?
(1) Of the marbles removed, the ratio of the number of red ones to the number of blue ones is 2 : 1. (2) Of the first 6 marbles removed, 4 are red.
A Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient. B Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient. C BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. D EACH Statement ALONE is sufficient. E Statements (1) and (2) TOGETHER are NOT sufficient.
A 1. 9 removed balls in R:B=2:1 =>6r and 3 B were removed hence answer can be found...suff 2. Incomplete info hence insuff
A jar contains 30 marbles, of which 20 are red and 10 are blue. If 9 of the marbles are removed, how many of the marbles left in the jar are red?
(1) Of the marbles removed, the ratio of the number of red ones to the number of blue ones is 2 : 1. (2) Of the first 6 marbles removed, 4 are red.
A Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient. B Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient. C BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. D EACH Statement ALONE is sufficient. E Statements (1) and (2) TOGETHER are NOT sufficient.
Statement 1 : suff since it gives the exact no.of marbles being removed.
Statement 2 : It talks abt the first 6 marbles.No info abt the latter 3 marbles.So nt suff.
There are 27 different three-digit integers that can be formed using only the digits 1, 2 and 3. If all 27 of the integers were listed, what would their sum be?
Hi, Can you help me with this? Please explain the method to reach the answers.
Q . A student is allowed to select at the most X books from a collection of (2X+1) books. If the total number of ways in which he can select book is 63,find the value of X.
