Official Quant thread for CAT 2013

MBA CAT 2024
21066
@bs0409 said:
OA-0Mr. X leaves his house daily at a particular time to go to his office. He reaches office 10 minutes late when he travels at 20 kmph and 5 minutes early when he travels at 30kmph. At what speed should he travel to reach office on time.
25.714?

regards
scrabbler
21067
@bs0409 said:
OA-0Mr. X leaves his house daily at a particular time to go to his office. He reaches office 10 minutes late when he travels at 20 kmph and 5 minutes early when he travels at 30kmph. At what speed should he travel to reach office on time.
180/7 km/hr ?

d/20 - d/x = 10/60.......i
d/x - d/30 = 5/60.........ii
solve i and ii

x = 180/7 km/hr
21068
@ChirpiBird said:
2?subtracted both equations.. got x=2 or x=3.
2And 3 toh satisfy bhi nai kar rahe....
21069
@bs0409 said:
OA-0Mr. X leaves his house daily at a particular time to go to his office. He reaches office 10 minutes late when he travels at 20 kmph and 5 minutes early when he travels at 30kmph. At what speed should he travel to reach office on time.
speed ratio is 2:3

time ratio 3:2

we need a difference of 15

so time ratio is 45:30

actual time taken is 35

then i am stuck :(
21070
@bs0409 said:
OA-0Mr. X leaves his house daily at a particular time to go to his office. He reaches office 10 minutes late when he travels at 20 kmph and 5 minutes early when he travels at 30kmph. At what speed should he travel to reach office on time.
speed ratio is 2:3

time ratio 3:2

we need a difference of 15

so time ratio is 45:30

actual time taken is 35

then i am stuck :(

21071
@bs0409 said:
OA-0Mr. X leaves his house daily at a particular time to go to his office. He reaches office 10 minutes late when he travels at 20 kmph and 5 minutes early when he travels at 30kmph. At what speed should he travel to reach office on time.
20(t+10/60)=30(t-5/60)
t=7/12 hr....d=20(7/12+10/60)=15 s=15/(7/12) 180/7km/hr
21072
@saurav205 said:
2And 3 toh satisfy bhi nai kar rahe....
@joyjitpal said:
same approach here but are 2 and 3 satisfying the equations@ChirpiBird
bache ki jaan loge kya!!! 😛 sorry.
I didnt see that.. [Image]
21073
@bs0409 said:
OA-0Mr. X leaves his house daily at a particular time to go to his office. He reaches office 10 minutes late when he travels at 20 kmph and 5 minutes early when he travels at 30kmph. At what speed should he travel to reach office on time.
180/7
21074
@bs0409 said:
1/5^903=2^903/10^903now last two digits of 2^903 are 08so ans=08How many common roots do 2 equation havex^3-7x^2+6x+1=0 & x^3-6x^2+x+7=01.02.33.24.45.none
equate both..
x=2 or 3...but neither satisfy..hence 0..
21075
@ChirpiBird said:
bache ki jaan loge kya!!! sorry. I didnt see that..
Arey chill...

21076
@bs0409 said:
1/5^903=2^903/10^903now last two digits of 2^903 are 08so ans=08How many common roots do 2 equation havex^3-7x^2+6x+1=0 & x^3-6x^2+x+7=01.02.33.24.45.none
equate both..
x=2 or 3...but neither satisfy..hence 0..
21077
@joyjitpal said:
speed ratio is 2:3time ratio 3:2we need a difference of 15so time ratio is 45:30actual time taken is 35then i am stuck @scrabbler@Logrhythm
T lekar kar lo...
Like t is the actual time taken...
Use the 2.condition given
Equate the distance
You get the on time waala t
Then get the distance
And d/t
21078
@bs0409 said:
OA-0Mr. X leaves his house daily at a particular time to go to his office. He reaches office 10 minutes late when he travels at 20 kmph and 5 minutes early when he travels at 30kmph. At what speed should he travel to reach office on time.
d/20=t+1/6
d/30=t-1/12
d/10(1/6)=3/12
d=15
t=7/12

Speed =180/7


21079
@joyjitpal said:
speed ratio is 2:3time ratio 3:2we need a difference of 15so time ratio is 45:30actual time taken is 35then i am stuck @scrabbler@Logrhythm
oh got it

then 30*30/35

gives 900/35 equal to 180/7

thanx

21080
@joyjitpal said:
speed ratio is 2:3time ratio 3:2we need a difference of 15so time ratio is 45:30actual time taken is 35then i am stuck @scrabbler@Logrhythm
bhai mere se TSD kabhi ratio se nahi hota...

but i guess what needs to be done here is 30*30/35 = 180/7

@scrabbler se confirm karwa lo but...
21081
@joyjitpal said:
i think 30 *30/35dekhlena thora
edited...typo srry.
21082
@joyjitpal said:
speed ratio is 2:3time ratio 3:2we need a difference of 15so time ratio is 45:30actual time taken is 35then i am stuck
So speed is 30/35 of 30 (or 45/35 of 20)

regards
scrabbler
21083

Find the remainder (30^72)^87 is divided by 11.

21084
@Exodia said:
Find the remainder (30^72)^87 is divided by 11.
5?
21085
@ChirpiBird said:
d/20=t+1/6d/30=t-1/12d/10(1/6)=3/12d=15t=7/12Speed =180/7
i am getting the answer 220/9