@ani4588 Correct !
@nramachandran said:Among four people A,B,C,D, A takes thrice as much time as B to complete a piece of work. B takes thrice as much time as C. C takes thrice as much time as D.. One group of three of the four men can complete the work in 13 days while another group of three can do it in 31 days. Which group takes 13 days?A,B,DB,C,DA,C,DA,B,C
Time Taken
A = 27d B = 9 d C = 3d D = d
Efficiency
A = 1% B = 3% C = 9% D = 27%
So A,B,D
If 999abc= def132,
then what will be a+b+c+d+e+f ?
then what will be a+b+c+d+e+f ?
@nramachandran said:Among four people A,B,C,D, A takes thrice as much time as B to complete a piece of work. B takes thrice as much time as C. C takes thrice as much time as D.. One group of three of the four men can complete the work in 13 days while another group of three can do it in 31 days. Which group takes 13 days?A,B,DB,C,DA,C,DA,B,C
say A does 1 unit of work per day
=>B does 3 units per day
=>C does 9 units per day
=>D does 27 units per day
say total work to be done = 13*31 units
now we can see that (A+B+D) =31 hence they would take (13*31)/31 = 13 days
(A+B+C) = 13 hence they would take (13*31)/31 = 31 days
Hence (A+B+D) would do the work in 13 days.
ATDH.
How many numbers between 1 to 1000 are not divisible by 2,3 or 5?
1000*1/2*2/3*4/5=1000*4/15=800/3=266
What is the logic behind this solution???
1000*1/2*2/3*4/5=1000*4/15=800/3=266
What is the logic behind this solution???
@vbhvgupta said:How many numbers between 1 to 1000 are not divisible by 2,3 or 5?1000*1/2*2/3*4/5=1000*4/15=800/3=266What is the logic behind this solution???
They are applying Euler's totient
Euler's totient may be defined as the number of numbers which are co-prime to the number(to which Euler's totient is calculated)
Euler's totient may be defined as the number of numbers which are co-prime to the number(to which Euler's totient is calculated)
A the math wizard, writes all natural numbers in order which do not use any prime digit. His first few numbers are 1, 4, 6, 8, 9, 10, 11, 14,..etc. What will be the 100th number that A writes?
Approach????
Approach????
are sab kahan gayab ho gaye aaj...
@vbhvgupta said:How many numbers between 1 to 1000 are not divisible by 2,3 or 5?1000*1/2*2/3*4/5=1000*4/15=800/3=266What is the logic behind this solution???
is the answer right?
Acc. to me the approach should be
1000/2=500(i.e no of numbers divisible by 2)-1(because 1000 is divisible by 2 but not included) == 499
1000/3=333(i.e no of numbers divisible by 3)
1000/5=200(i.e no of numbers divisible by 5)-1 ==199
ADD the three you get 1031.
Now find the numbers which are divisible by 2,3 or 3,5 or 2,5 and subtract from the answer
1000/6=166
1000/10=100-1 == 99
1000/15=66
add you will get 331
therefore 1031-331=700
Now find the numbers divisible by 2,3,5 i.e 1000/30=33 and add this from the answer == 700+33=733(this step you wil understand if you relate it to a three set venn diagram)
Therefore there are 667 numbers out of 998 numbers divisible by either 2,3,5 so the no of numbers not divisible by 2,3,5 will be 998-733=265
is my answer right?
Acc. to me the approach should be
1000/2=500(i.e no of numbers divisible by 2)-1(because 1000 is divisible by 2 but not included) == 499
1000/3=333(i.e no of numbers divisible by 3)
1000/5=200(i.e no of numbers divisible by 5)-1 ==199
ADD the three you get 1031.
Now find the numbers which are divisible by 2,3 or 3,5 or 2,5 and subtract from the answer
1000/6=166
1000/10=100-1 == 99
1000/15=66
add you will get 331
therefore 1031-331=700
Now find the numbers divisible by 2,3,5 i.e 1000/30=33 and add this from the answer == 700+33=733(this step you wil understand if you relate it to a three set venn diagram)
Therefore there are 667 numbers out of 998 numbers divisible by either 2,3,5 so the no of numbers not divisible by 2,3,5 will be 998-733=265
is my answer right?
@vbhvgupta said:How many numbers between 1 to 1000 are not divisible by 2,3 or 5?1000*1/2*2/3*4/5=1000*4/15=800/3=266What is the logic behind this solution???
is the answer right?
Acc. to me the approach should be
1000/2=500(i.e no of numbers divisible by 2)-1(because 1000 is divisible by 2 but not included) == 499
1000/3=333(i.e no of numbers divisible by 3)
1000/5=200(i.e no of numbers divisible by 5)-1 ==199
ADD the three you get 1031.
Now find the numbers which are divisible by 2,3 or 3,5 or 2,5 and subtract from the answer
1000/6=166
1000/10=100-1 == 99
1000/15=66
add you will get 331
therefore 1031-331=700
Now find the numbers divisible by 2,3,5 i.e 1000/30=33 and add this from the answer == 700+33=733(this step you wil understand if you relate it to a three set venn diagram)
Therefore there are 667 numbers out of 998 numbers divisible by either 2,3,5 so the no of numbers not divisible by 2,3,5 will be 998-733=265
is my answer right?
Acc. to me the approach should be
1000/2=500(i.e no of numbers divisible by 2)-1(because 1000 is divisible by 2 but not included) == 499
1000/3=333(i.e no of numbers divisible by 3)
1000/5=200(i.e no of numbers divisible by 5)-1 ==199
ADD the three you get 1031.
Now find the numbers which are divisible by 2,3 or 3,5 or 2,5 and subtract from the answer
1000/6=166
1000/10=100-1 == 99
1000/15=66
add you will get 331
therefore 1031-331=700
Now find the numbers divisible by 2,3,5 i.e 1000/30=33 and add this from the answer == 700+33=733(this step you wil understand if you relate it to a three set venn diagram)
Therefore there are 667 numbers out of 998 numbers divisible by either 2,3,5 so the no of numbers not divisible by 2,3,5 will be 998-733=265
is my answer right?
@iLoveTorres said:is the answer right?Acc. to me the approach should be 1000/2=500(i.e no of numbers divisible by 2)-1(because 1000 is divisible by 2 but not included) == 4991000/3=333(i.e no of numbers divisible by 3)1000/5=200(i.e no of numbers divisible by 5)-1 ==199ADD the three you get 1031.Now find the numbers which are divisible by 2,3 or 3,5 or 2,5 and subtract from the answer1000/6=1661000/10=100-1 == 991000/15=66add you will get 331therefore 1031-331=700Now find the numbers divisible by 2,3,5 i.e 1000/30=33 and add this from the answer == 700+33=733(this step you wil understand if you relate it to a three set venn diagram)Therefore there are 667 numbers out of 998 numbers divisible by either 2,3,5 so the no of numbers not divisible by 2,3,5 will be 998-733=265is my answer right?
bro ans is 266
@vbhvgupta said:A the math wizard, writes all natural numbers in order which do not use any prime digit. His first few numbers are 1, 4, 6, 8, 9, 10, 11, 14,..etc. What will be the 100th number that A writes?Approach????
Is this 488? I am trying some weird logic here....if it is matching will explain...
regards
scrabbler
regards
scrabbler
@scrabbler said:Is this 488? I am trying some weird logic here....if it is matching will explain...regardsscrabbler
bhai, I dont have OA......plz explain ur logic
@vbhvgupta said:A the math wizard, writes all natural numbers in order which do not use any prime digit. His first few numbers are 1, 4, 6, 8, 9, 10, 11, 14,..etc. What will be the 100th number that A writes?
Approach????
had he written all numbers without removing any prime 100th number would be = 100
now that we have 25 prime numbers from 1 to 100
remove 25 prime numbers from 1 to 100
so the 100th number moves to 125.
now there are 5 prime numbers from 101 to 125
so the number moves to 130
now there is 1 prime numbers from 126 to 130
so the number is 131but 131 is also prime
so 132??
@chandrakant.k said:had he written all numbers without removing any prime 100th number would be = 100now that we have 25 prime numbers from 1 to 100remove 25 prime numbers from 1 to 100so the 100th number moves to 125.now there are 5 prime numbers from 101 to 125so the number moves to 130now there is 1 prime numbers from 126 to 130so the number is 131but 131 is also primeso 132??
options (A) 144(B) 266(C) 488(D) 699(E) none of these
@vbhvgupta said:A the math wizard, writes all natural numbers in order which do not use any prime digit. His first few numbers are 1, 4, 6, 8, 9, 10, 11, 14,..etc. What will be the 100th number that A writes?Approach????
the digits he has are 0,1,4,6,8,9 (i.e 6 digits) so the counting would be in a base of six
in this base of 6,
first digit is 0,
second digit =1,
third digit=4,
fourth digit = 6,
fifth digit=8 and
sixth digit =9
value of 100 when converted in base of 6 = 244
so replacing the third digit and 5th digit from the above list we get 488.
ATDH.
@anytomdickandhary said:the digits he has are 0,1,4,6,8,9 (i.e 6 digits) so the counting would be in a base of sixin this base of 6, first digit is 0, second digit =1, third digit=4, fourth digit = 6, fifth digit=8 and sixth digit =9value of 100 when converted in base of 6 = 244so replacing the third digit and 5th digit from the above list we get 488.ATDH.
yar didnt get the logic? 
@vbhvgupta said:options (A) 144(B) 266(C) 488(D) 699(E) none of these
My take none of these 😁 or i am seriously misunderstood the question
Well i am getting 130 as the number
Earlie miscalculated.
Now i have written down in the paper
@anytomdickandhary said:the digits he has are 0,1,4,6,8,9 (i.e 6 digits) so the counting would be in a base of sixin this base of 6, first digit is 0, second digit =1, third digit=4, fourth digit = 6, fifth digit=8 and sixth digit =9value of 100 when converted in base of 6 = 244so replacing the third digit and 5th digit from the above list we get 488.ATDH.
@chandrakant.k yar tumhe ye samajh me aaya???
2 women and 3 men complete the work in 4 days, While 3 women and 2 men complete the work in 5 days. rs 44 is given to woman for her contribution towards work per day. what is the amount received by man per day.