what should be approach in this case????
@gs4890 bhai the way to calucalte the sum till n is n*euler(n) but here it is asked less than 300 and prime to 150
@TootaHuaDil said:Rem(123123123.....300 digits)/504?
504 = 7*8*9
Divisibility rule for 8 :- check for last 3 digits . 123 /8 ==> rem = 3 " 8a+3"
Divisibilty rule for 9 :- check for sum = 100 * (1+2+3) / 9 ==> 600/9 ==> rem = 6 "9b+6"
Divisibility rule for 7 :- difficult to apply the rule..
1000/7 ==> rem = -1 . 123 *( 10^3 )^99+ 123 * (10^3)^98 +..........123 *10^3 + 123 / 7 .
so its 0 ... 7c .
8a+3 = 9b+6 = 7c . from options u can go..ans ll be 483
Divisibility rule for 8 :- check for last 3 digits . 123 /8 ==> rem = 3 " 8a+3"
Divisibilty rule for 9 :- check for sum = 100 * (1+2+3) / 9 ==> 600/9 ==> rem = 6 "9b+6"
Divisibility rule for 7 :- difficult to apply the rule..
1000/7 ==> rem = -1 . 123 *( 10^3 )^99+ 123 * (10^3)^98 +..........123 *10^3 + 123 / 7 .
so its 0 ... 7c .
8a+3 = 9b+6 = 7c . from options u can go..ans ll be 483
@naveenkrs said:Try this -Find the sum of all positive integers less than 300 and relatively prime to 150.
@gs4890 said:300(1-1/2)(1-1/5)(1-1/3)=> 80 ?
@karan20 said:bhai , i guess 80 wil be the count of such nos. SUM shud be 150 x 80 = 12000...correct me if m wrong..
@gs4890 said:
@ravi.theja said:300 = 5^2 * 3 * 2^2E ( 300 ) = 300 * 4/5 * 2/3* 1/2 = 80 .Sum of all co-primes less than 150 = 150/2 * 80 = 6000??
@ravi.theja said:bhai if its less than 300 then its 300/2 * 80 ........but here its asked for less than 150 so shud it be 150/2 * 80 ?? correct me if m wrng
@techsurge said:whats the OA, know only how to calculate less than 150
@techsurge said:@gs4890 bhai the way to calucalte the sum till n is n*euler(n) but here it is asked less than 300 and prime to 150what should be approach in this case????
OA = 12000
Sum of all positive integers less than 2n and relatively prime to n. = 2n*E(n)
@naveenkrs said:OA = 12000Sum of all positive integers less than 2n and relatively prime to n. = 2n*E(n)
clear now !! tanx !! gt d logic 
@naveenkrs said:Try this -Find the sum of all positive integers less than 300 and relatively prime to 150.
E(300) = 80
sum of all co-primes = 300*80/2 = 12000
@veertamizhan said:2 coins are going to be flipped>It is guaranteed that at least one out of the two flips will turn up heads What is the probability that both coins will come up heads?
total cases = 2*2 - 1 = 3
favorable case = 1
prob. = 1/3
@naveenkrs said:Try this -Find the sum of all positive integers less than 300 and relatively prime to 150.
@naveenkrs said:Try this -Find the sum of all positive integers less than 300 and relatively prime to 150.
80 hoga kya ?
@veertamizhan said:2 coins are going to be flipped>It is guaranteed that at least one out of the two flips will turn up heads What is the probability that both coins will come up heads?
1/3
@jain4444 said:E(300) = 80 sum of all co-primes = 300*80/2 = 12000
Bro can u please explain why u divided by 2..
Bro can u please explain why u divided by 2..
use formula of summation of an AP 
:drink:
:drink:
Some numbers can be expressed as the sum of three of their factors. E.g. 12 can be expressed as
the sum of 2, 4 and 6. How many other such numbers are there which are less than 100?
the sum of 2, 4 and 6. How many other such numbers are there which are less than 100?
@nramachandran said:Some numbers can be expressed as the sum of three of their factors. E.g. 12 can be expressed asthe sum of 2, 4 and 6. How many other such numbers are there which are less than 100?
100/6 equal to 16 such nos are there
@nramachandran said:Some numbers can be expressed as the sum of three of their factors. E.g. 12 can be expressed as
the sum of 2, 4 and 6. How many other such numbers are there which are less than 100?
is it strictly 3, or equal to greater than three?
12 has four factors 2,3,4,6 :neutral:
@nramachandran said:Bro can u please explain why u divided by 2..
formula for sum of numbers relatively prime to N and less than N
is N/2*E( N)
is N/2*E( N)
@vijay_chandola said:is it strictly 3, or equal to greater than three?12 has four factors 2,3,4,6
strictly 3 :)
@joyjitpal said:100/6 equal to 16 such nos are there
Bro, there is a trap here 😃 "How many other such numbers are there "
So we should not be including 12
So multiples of 6 other than 12,so answer is 15
@nramachandran said:Bro can u please explain why u divided by 2..
if a is co-prime to 300 then (300 - a) will also be co-prime to 300
now , a + (300 - a) = 300 that's why divided by 2
@nramachandran said:Bro, there is a trap here "How many other such numbers are there "So we should not be including 12So multiples of 6 other than 12,so answer is 15
thanx for notifying it :)
the average weight of a group of n people is 75 kg.three men whose weights are 80,76,74 kg join the group and one man weighing between 90 to 100kg leave the group as a result average came down by 2 kg . if the number of men initially is a perfect square .then the weight of men who left the group is ?
92
94
96
98