@scrabbler Though it won't have any effect on answer but i think 10! * (1 + E+E+E....) there all numbers won't be E right ? they should be different even numbers. right ?10 ! * (E+1) (odd number) even number * odd number = even number ( i think so) so how do we know in final term there are only 8 2's ? I may be horribly wrong here,but this is what i understood.
E refers to a generic even number. I intended it as a variable... I am using the property that sum of any number of evens is even only....and if I add 1 to a bunch of evens, we will get odd... regards scrabbler
Climbing up on a moving escalator,Ram can reach the first floor frm ground floor in 30 sec.If he climbs up on stationary stairs,he takes 20 secs to reach first floor.How many secs will he take for the same trip if he climbs up with his standard pace in the direction of an escalator going up?
Climbing up on a moving escalator,Ram can reach the first floor frm ground floor in 30 sec.If he climbs up on stationary stairs,he takes 20 secs to reach first floor.How many secs will he take for the same trip if he climbs up with his standard pace in the direction of an escalator going up?
like i meant if i take say he doesnt score 20 runs and scores 56 runs so effectively he is scoring 36 runs. if you relate it to the original problem this has to align somewhere right?
No, he doesn't score 20 in one innings less than current OR he scored 56 in one more than current. n changes.
Had it said, instead of scoring 20 in his last innings he scored 56, then n would remain same but total n*a would increase by 36, so average would increase by 36/n regards scrabbler
i have posted this 4-5 times before in pg,m posting again coz m not getting it.i hope it doesn't amount to spamming,
A teacher wanted to adminster a multiple choice(each question having six choices) based quiz of high difficulty level to a class of sixty students.The quiz had sixty questions.The probability of selecting the correct answer for a good and brilliant student was 0.2 and 0.25 respectively.All the students were seated serially in 10 rows and 6 columns.
q) three good students were seated next to each other.What is the probability of them having the same incorrect choice for four consecutive questions ?
i did it like
to get one incorrect answer, probabilty is 1/5
so all INCORRECT for one student is 1/5*1/5*1/5*1/5
so overall for 3 students (1/5*1/5*1/5*1/5)^3 but it is not in options.where did i go wrong ?
Climbing up on a moving escalator,Ram can reach the first floor frm ground floor in 30 sec.If he climbs up on stationary stairs,he takes 20 secs to reach first floor.How many secs will he take for the same trip if he climbs up with his standard pace in the direction of an escalator going up?
His speeds (Upstream, stationary and downstream) will be in AP. So U - S = S - D
If n is number of steps, we can say n/30 - n/20 = n/20 - n/t where t is the time "downstream".
let ram take 1 step/sec and escalator take n steps/sec therefore 30-30n=20 ==> n=1/3 now when the escalator is moving up by the time ram takes 3 steps escalator takes one step so he has to take 20 steps i.e 20/4=5 such cycles but for 3 steps ram takes 3 sec so totally 15 sec
@Estallar12 If you don't mind can you explain me how to proceed from thisA=10! + 12 ! + 14 !...... 100 !A= 10 ! (1 + 12*11 + 14*13*12*11 + ...... 100!/10!))Is the answer possible if we proceed from this angle ?
Oh Damn!
A = 10! + 12! + 14! and so on.
I took it as A = 10! + 11! + 12! ... + 100! 😲 :splat:
this is how i did..let number of stairs on escalator and normal stairs be Nv= persons speed. u= escalator speedN/v=20or N=20vnow (N+(N/v)u)/v=30where (N+(N/v)u) is the length of the escalator
Where did this come from? Too many variables....core dump ho raha hai...sorry! :)
