Try this
1!*2!*3!*4!* 5!*6!*... ......... ......100! .find the number of zero?
hey plz help!! yar how do u do that addition table question?? i guess u must have had encountered it by now from power prep!!
plz explain my exam is in on tuesday! that is the only question i cant make out!!
hey plz help!! yar how do u do that addition table question?? i guess u must have had encountered it by now from power prep!!
plz explain my exam is in on tuesday! that is the only question i cant make out!!
Can u please post the q for everyone's benefit.
its a table i cant make it here! it reads solve the addition table
Good one!!
Bill has a small deck of 12 playing cards made up of only 2 suits of 6 cards each. Each of the 6 cards within a suit has a different value from 1 to 6; thus, there are 2 cards in the deck that have the same value.
Bill likes to play a game in which he shuffles the deck, turns over 4 cards, and looks for pairs of cards that have the same value. What is the chance that Bill finds at least one pair of cards that have the same value?
A. 8/33
B. 62/165
C. 17/33
D. 103/165
E. 25/33
The greatest common factor of 16 and the positive integer n is 4, and the greatest common factor of n and 45 is 3. Which of the following could be the greatest common factor of n and 210?
A3
B14
C30
D42
E70
Eighty percent of the lights at Hotel California are switched on at 8 p.m. one evening. However, forty percent of the lights that are supposed to be switched off are actually switched on, and ten percent of the lights that are supposed to be switched on are actually switched off. What percent of the lights that are switched on are supposed to be switched off?
A22(2/9)%
B16(2/3)%
C11(1/9)%
D10%
E5%
Try this
1!*2!*3!*4!* 5!*6!*... ......... ......100! .find the number of zero?
One zero is generated when we have one 2 and one 5 ...since no of 2's are more than no of 5, count the no of 5's in the above product ...
Now, this can be done by using integer rule ...
From 1 to 4 ! does not contribute a 5 ...
From 5! to 9! each of the five nos contribute one 5 ........1
From 10! to 14! each of the five nos contribute two 5 .....2
.
.
. ( continue the trend)
15! to 19! ...3
Hence total no of zeros are
5 ( 1+2+3+4+6+7+8+9+10+12+13+14+15+16+18+19+20+21+22+24)
= 5 [ summation 24 - ( 5+11+17+23)
=5 [ (24*25/2) - 56)
= 5 [ 300 - 56 ]
=5 * 244
= 1220 zeros ..
P.S: eg to calculate no of 5's in 56! use the rule
[56/5] + [56/5^2] = 11 + 2 = 13 ...hence every no from 55! to 59! each of the nos contribute 13 5's ( where [ ] respresents integral value )
OA pls ?
The greatest common factor of 16 and the positive integer n is 4, and the greatest common factor of n and 45 is 3. Which of the following could be the greatest common factor of n and 210?
A 3
B 14
C 30
D 42
E 70
If HCF of 16 and n is 4 then
n= 2^2 * k ( where k is not a multiple of 2 )
If HCF of 45 and n is 3, then
n = 3 * p ( where p is not a multiple of 3 or 5 )
Hence, p = 2^2 * 3 * q ( where q =p*k, which is neither a multiple of 2,3,or 5)
210 = 2*3*5*7
p = 2^2 * 3 * q
Hence, HCF = 2*3*7 = 42 ( q has to be a multiple of 7, since it cannot be 2,3 or 5)
Ans D ...
Will solve remaining tomm
Try this
1!*2!*3!*4!* 5!*6!*... ......... ......100! .find the number of zero?
Is the ans 1009 ...Please post the OA
Good one!!
Bill has a small deck of 12 playing cards made up of only 2 suits of 6 cards each. Each of the 6 cards within a suit has a different value from 1 to 6; thus, there are 2 cards in the deck that have the same value.
Bill likes to play a game in which he shuffles the deck, turns over 4 cards, and looks for pairs of cards that have the same value. What is the chance that Bill finds at least one pair of cards that have the same value?
A. 8/33
B. 62/165
C. 17/33
D. 103/165
E. 25/33
Prob that there is no pair :
1st card = random selection, no prob involved
2nd card = shd not be the corr card, hence 10/11
3rd card = shd not be the corr prev 2 cards, hence 8/10
4th card = shd not be the corr prev 3 cards, hence 6/9
Prob ( no pair) = 1 * 10/11 * 8/10 * 6/9 = 16/33
Hence, p(atleast 1 pair) = 1 - 16/33 = 17/33 ..Ans C
The greatest common factor of 16 and the positive integer n is 4, and the greatest common factor of n and 45 is 3. Which of the following could be the greatest common factor of n and 210?
A3
B14
C30
D42
E70
I wud go with option D
Eighty percent of the lights at Hotel California are switched on at 8 p.m. one evening. However, forty percent of the lights that are supposed to be switched off are actually switched on, and ten percent of the lights that are supposed to be switched on are actually switched off. What percent of the lights that are switched on are supposed to be switched off?
A22(2/9)%
B16(2/3)%
C11(1/9)%
D10%
E5%
Is the ans for the above q option d)10%.Here is how I worked it out
Total no.of lights = 100
Suppose to be: switched ON = 80 and switched OFF = 20.
Real condition : ON = 72 + 8
OFF = 12 + 8
So the actual percentage is 8/80 * 100 = 10%
Eighty percent of the lights at Hotel California are switched on at 8 p.m. one evening. However, forty percent of the lights that are supposed to be switched off are actually switched on, and ten percent of the lights that are supposed to be switched on are actually switched off. What percent of the lights that are switched on are supposed to be switched off?
A 22(2/9)%
B 16(2/3)%
C 11(1/9)%
D 10%
E 5%
Let x%= Ideally ON
y%= ideally OFF
x+y = 100 ....(1)
Now, Ideal Vs Actual
Actual ON = 0.9x + 0.4y
So, 0.9x + 0.4y = 80 ...(2)
Solve, simultaneously,
x = 80 ; y = 20
Now, from these 80, 0.4y i.e 0.4*20 = 8 shd have been OFF
Hence, Ans = 8/80 = 10 %
Ans D
Try this one :
What is the tens digit of 7^202?
deepakraam SaysI wud go with option D
I think option (D) is the correct answer!
Try this one :
What is the tens digit of 7^202?
Ans : 4 ....
Cyclicity is 4 ...
for 7^4n and 7^(4n+1) ...tens digit is 0
for 7^(4n+2) and 7^(4n+3) ....tens digit is 4 ...
Deepak, wats d OA for the no of zeros sum ?
Ans : 4 ....
Cyclicity is 4 ...
for 7^4n and 7^(4n+1) ...tens digit is 0
for 7^(4n+2) and 7^(4n+3) ....tens digit is 4 ...
Deepak, wats d OA for the no of zeros sum ?
correct ans is 4.For the no.of zero's sum i got ans as 1024.I dunt have the ans.Got it some blog.
deepakraam Sayscorrect ans is 4.For the no.of zero's sum i got ans as 1024.I dunt have the ans.Got it some blog.
For zero's sum, can u discuss your approach too?
Ans : 4 ....
Cyclicity is 4 ...
for 7^4n and 7^(4n+1) ...tens digit is 0
for 7^(4n+2) and 7^(4n+3) ....tens digit is 4 ...
Deepak, wats d OA for the no of zeros sum ?
bhavin,
can u explain the part in bold a lil more...
thanks!!