@bhatkushal said:Q)How many pairs of previous integers (m,n) satisfy the equation:-1/m!+1/n!=1/20?a 0b 1c 2d 3
can some one tell the approach for this
@bhatkushal said:For how many positive integers n,less than or equal to 50 is (n-1)! divisible by n?a 16b 33c 32d non of these
34?
@bhatkushal said:Q)How many pairs of previous integers (m,n) satisfy the equation:-1/m!+1/n!=1/20?a 0b 1c 2d 3
0?
@bhatkushal said:Q)How many pairs of previous integers (m,n) satisfy the equation:-1/m!+1/n!=1/20?a 0b 1c 2d 3
2
1/4!+1/5!
1/4!+1/5!
@bhatkushal said:Q)How many pairs of positive integers (m,n) satisfy the equation:-1/m!+1/n!=1/20?a 0b 1c 2d 3
@gupanki2 said:@mailtoankit yaar koi iss waley answer ki approach bataooo.... question hi samjh nahi aaraha yahah toh
kon sa Q bhai??
@mailtoankit said:kaise hoga??
choose the 4 distinct nos. --> 6c4
now, each of them can of any of the 2 suits --> *2 for each card --> 6c4*2^4
prob.--> 6C4*2^4/12C4 = 16/33
now, each of them can of any of the 2 suits --> *2 for each card --> 6c4*2^4
prob.--> 6C4*2^4/12C4 = 16/33
@bhatkushal said:yaar approach to batao........
yaar aise question ka koi approach nai hota, just notice that after 5! the denominator increases too fast for the sum to be 1/20, just hit and trial
@bhatkushal said:yaar approach to batao........
let x = m! ; y = n!
1/x + 1/y =1/20
--> (x-20)(y-20) =400
one f the solns . is 4 * 100 --> x=24; y=100
--> m=4;n=5
1/x + 1/y =1/20
--> (x-20)(y-20) =400
one f the solns . is 4 * 100 --> x=24; y=100
--> m=4;n=5
X is a three-digit number. The sum of all its distinct prime factors is 17. What is the value of X?
I. X > 420
II. The total number of factors of X is 24. X ‰¤ 630
if each statement alone is sufficient to answer the question.
if statements I and II together are sufficient but neither statement alone is sufficient to answer the question.
if the two statements I and II together are not sufficient to answer the question and additional data is needed.
I. X > 420
II. The total number of factors of X is 24. X ‰¤ 630
if statement I alone is sufficient and statement II alone is not sufficient to answer the question
if statement II alone is sufficient and statement I alone is not sufficient to answer the question.
if statement II alone is sufficient and statement I alone is not sufficient to answer the question.
if each statement alone is sufficient to answer the question.
if statements I and II together are sufficient but neither statement alone is sufficient to answer the question.
if the two statements I and II together are not sufficient to answer the question and additional data is needed.
@bullseyes said:X is a three-digit number. The sum of all its distinct prime factors is 17. What is the value of X?I. X > 420II. The total number of factors of X is 24. X ‰¤ 630if statement I alone is sufficient and statement II alone is not sufficient to answer the questionif statement II alone is sufficient and statement I alone is not sufficient to answer the question.if each statement alone is sufficient to answer the question.if statements I and II together are sufficient but neither statement alone is sufficient to answer the question.if the two statements I and II together are not sufficient to answer the question and additional data is needed.
I and II 2gether are sufficient . bt nt alone
@bullseyes said:X is a three-digit number. The sum of all its distinct prime factors is 17. What is the value of X?I. X > 420II. The total number of factors of X is 24. X ‰¤ 630if statement I alone is sufficient and statement II alone is not sufficient to answer the questionif statement II alone is sufficient and statement I alone is not sufficient to answer the question.if each statement alone is sufficient to answer the question.if statements I and II together are sufficient but neither statement alone is sufficient to answer the question.if the two statements I and II together are not sufficient to answer the question and additional data is needed.
X=2^a*3^b*5^c*7^d
lowest X=210, number of factors = 16
from II, X=420,630
from I and II, x=630
so I and II both are needed
lowest X=210, number of factors = 16
from II, X=420,630
from I and II, x=630
so I and II both are needed
@krum said:X=2^a*3^b*5^c*7^dlowest X=210, number of factors = 16from II, X=420,630from I and II, x=630so I and II both are needed
why the no. cant be 289?? using 1st statement alone
answer is given as (both are req. though)
@bullseyes said:X is a three-digit number. The sum of all its distinct prime factors is 17. What is the value of X?I. X > 420II. The total number of factors of X is 24. X ‰¤ 630if statement I alone is sufficient and statement II alone is not sufficient to answer the questionif statement II alone is sufficient and statement I alone is not sufficient to answer the question.if each statement alone is sufficient to answer the question.if statements I and II together are sufficient but neither statement alone is sufficient to answer the question.if the two statements I and II together are not sufficient to answer the question and additional data is needed.
Both 1 and 2 are needed to answer the question
From 1 we cannot conclude anything since the number can be any one of 630,840...
From 2 we know that the no is less than or equal to 630 and the no can be any among 420 and 630
So from 1 and 2 we can conclude that the number is 630