@ganeshv266 said:what is the remainder when 20! is divided by 23?? please share the approach..
11 ?
(p - 1)! mod p = p - 1
22! mod 23 = 22
22*21*20! mod 23 = 22
-2*-1*20! mod 23 = 22
20! mod 23 = 11
@dream_BLAC_2013 said:@[email protected]@ziddiarmaanCan someone plz try this DS sum? A & B start from two ends of a swimming pool 50m long simultaneously. What is the total distance distance covered by them?A. They are meeting 2nd time after startB. A's speed is twice that of B's.I know that this sum looks very simple. I just cant makeout if this book has a printing mistake in the answer keys or is there any hidden factor that I am missing. Plz help.
??
@ziddiarmaan said:What is the remainder when 25^889 is divided by 99?
99 = 9*11
phi(9) = 6 i.e. 25^6k = 1 mod 9 as HCF(25, 9) = 1
phi(11) = 10 i.e. 25^10k = 1 mod 11 as HCF(25, 11) = 1
That means 25^30k = 1 mod 99 as LCM(6, 10) = 30
So, 25^889 = 5^1778 = 5^8 mod 99 = 625^2 = 31^2 mod 99 = 961 = -29 mod 99 = 70 mod 99. :)
Alternately, you could have solved by 9 and 11 individually and combine them.
Team BV - Kamal Lohia
phi(9) = 6 i.e. 25^6k = 1 mod 9 as HCF(25, 9) = 1
phi(11) = 10 i.e. 25^10k = 1 mod 11 as HCF(25, 11) = 1
That means 25^30k = 1 mod 99 as LCM(6, 10) = 30
So, 25^889 = 5^1778 = 5^8 mod 99 = 625^2 = 31^2 mod 99 = 961 = -29 mod 99 = 70 mod 99. :)
Alternately, you could have solved by 9 and 11 individually and combine them.
Team BV - Kamal Lohia
@dream_BLAC_2013
i dont get it.. do we have to calculate the total distance covered by both of them when they meet for the second time..??
i dont get it.. do we have to calculate the total distance covered by both of them when they meet for the second time..??
@ganeshv266 said:@dream_BLAC_2013i dont get it.. do we have to calculate the total distance covered by both of them when they meet for the second time..??
He wrote it above the sum its a Data Sufficiency problem 
@dream_BLAC_2013 said:@[email protected]@ziddiarmaanCan someone plz try this DS sum? A & B start from two ends of a swimming pool 50m long simultaneously. What is the total distance distance covered by them?A. They are meeting 2nd time after startB. A's speed is twice that of B's.I know that this sum looks very simple. I just cant makeout if this book has a printing mistake in the answer keys or is there any hidden factor that I am missing. Plz help.
ratio of speed = ratio of distance covered
so i guess statement 2 is enough to conclude ?
@MANC-LONDON said:@Buck.up gd job....
@next_big_thing said:@techgeek2050 I am really really thankful for taking the pain of going through such a cumbersome process for making a stranger understand Thanks alooot
pls..dont spam here...I understand u want to appreciate people so,if u want to thank them..pm them..dont clutter this post
@MANC-LONDON said:@Buck.up gd job....
@next_big_thing said:@techgeek2050 I am really really thankful for taking the pain of going through such a cumbersome process for making a stranger understand Thanks alooot
plz...don't spam.
I understand you want to appreciate people so,,u shud pm them to thank them or appreciate them.
@Logrhythm said:ratio of speed = ratio of distance coveredso i guess statement 2 is enough to conclude ?
But how many times they make to and fro movement can't be concluded and hence the distance.
i think both the statements are needed
From statement 1: We can say for first meeting they travel 50 m. But, we cannot calculate distance between first and second meeting..
Statement 2 alone does not give any distance as such. But, combined with statement 1, we can find out distance between first and second meeting.
So, both are needed..
@dream_BLAC_2013 said:@[email protected]@ziddiarmaanCan someone plz try this DS sum? A & B start from two ends of a swimming pool 50m long simultaneously. What is the total distance distance covered by them?A. They are meeting 2nd time after startB. A's speed is twice that of B's.I know that this sum looks very simple. I just cant makeout if this book has a printing mistake in the answer keys or is there any hidden factor that I am missing. Plz help.
ratio of speed = ratio of distance
so 2 alone ??
@dream_BLAC_2013 said:@[email protected]@ziddiarmaanCan someone plz try this DS sum? A & B start from two ends of a swimming pool 50m long simultaneously. What is the total distance distance covered by them?A. They are meeting 2nd time after startB. A's speed is twice that of B's.I know that this sum looks very simple. I just cant makeout if this book has a printing mistake in the answer keys or is there any hidden factor that I am missing. Plz help.
@Logrhythm said:ratio of speed = ratio of distance coveredso i guess statement 2 is enough to conclude ?
But yaar! How many times they make to and fro movement can't be concluded..and hence the distance
@dream_BLAC_2013 said:@[email protected]@ziddiarmaanCan someone plz try this DS sum? A & B start from two ends of a swimming pool 50m long simultaneously. What is the total distance distance covered by them?A. They are meeting 2nd time after startB. A's speed is twice that of B's.I know that this sum looks very simple. I just cant makeout if this book has a printing mistake in the answer keys or is there any hidden factor that I am missing. Plz help.
EDIT : both are required ??
total distance covered by them after 2nd meet = 50 + 2*50 = 150
dist. covered by A = 2/3*150 = 100
dist by B = 1/3*150 = 50
@Buck.up said:But yaar! How many times they make to and fro movement can't be concluded..and hence the distance
ok i had misread the question....it says "what is the total distance covered by them"
statement 1 - they meet for the second time
statement 2 - Va:Vb = 2:1
statment1 + statement2 = meeting for the second time and ratio of distance covered by A and B would be 2:1
so i guess both the statements would be needed
the language of this question seems a little ambiguous to me though
@mailtoankit bhai what do u think?
@dream_BLAC_2013 said:
A & B start from two ends of a swimming pool 50m long simultaneously. What is the total distance distance covered by them?A. They are meeting 2nd time after startB. A's speed is twice that of B's.I know that this sum looks very simple. I just cant makeout if this book has a printing mistake in the answer keys or is there any hidden factor that I am missing. Plz help.
both the statements are needed...
Since statement B gives us the ratio of time/speeds of A & B.
the total distance covered is uptill the second time they meet.
@Buck.up said:But yaar! How many times they make to and fro movement can't be concluded..and hence the distance
i misread the ques....both would be required
@Logrhythm said:i misread the ques....both would be required
bhai starting 2 ends se kar rahe hai or total distance nikalna hai...1st statement se hi aa raha hai ans....total dist = 50 + 2*50 = 150 (after second meet)??
@mailtoankit said:bhai starting 2 ends se kar rahe hai or total distance nikalna hai...1st statement se hi aa raha hai ans....total dist = 50 + 2*50 = 150 (after second meet)??
par we dont know the their speeds so how can we know about distance covered....is second statement is not there