@sujamait said:ek Q ...In an over 7 runs were scored..only 0,1,2,3,4,6 runs on a ball are possible.what is the probability of atleast one dot ball(0 rum) by the batsmen.
119/120??
@pari19O1 said:1013??2W8C, 3W7C, 4W6C, 5W5C, 6W4C,7W3C,8W2C,9W1C,10W...and solve...
Do it the opposite way, the calculation is easier, i.e. 10C0W and 9C1W.
@sujamait said:In how many ways can sachin attempt all the Questions with atleast 2 mistakes of a test having 10 Questions ?
10-right..0 wrong........9 right...1 wrong
2^10-11=1013??..sahi hai kya sir??
@sujamait said:ek Q ...In an over 7 runs were scored..only 0,1,2,3,4,6 runs on a ball are possible.what is the probability of atleast one dot ball(0 rum) by the batsmen.
X1+x2....+x6=7
12C5= 792
Removing 700000, 520000, 511000
792-96=696
211111 only case with no zeroes. =6 ways
So, reqd probability =690/696=115/116
@joyjitpal said:a teacher asked a student to add nine 2-digit no. such that each no. is 10 more than the previous no. but the student has added all the no.,which are formed by interchanging the digits of each of the given no.surprisingly,the sum he got was the same as the sum the teacher has asked for.which of the following is the difference of the digits in the least of the no. the student was asked to add? a) 2 b) 3 c)4d) 5
4??
@sujamait said:In how many ways can sachin attempt all the Questions with atleast 2 mistakes of a test having 10 Questions ?
10C2 + 10C3 + ...... + 10C10 = 1013 ?
@sujamait said:ek Q ...In an over 7 runs were scored..only 0,1,2,3,4,6 runs on a ball are possible.what is the probability of atleast one dot ball(0 rum) by the batsmen.
a + b + c + d + e + f = 7
Total = C(12, 5) ways
But ee need to remove (7, 0, 0, 0, 0, 0), (5, 1, 1, 0, 0, 0) and (5, 2, 0, 0, 0, 0)
So, C(12, 5) - 6 - 6!/(2!3!) - 6!/4! = 696 ways
Required probability = 1 - 6/696 = 1 - 1/116 = 115/116
@joyjitpal said:a teacher asked a student to add nine 2-digit no. such that each no. is 10 more than the previous no. but the student has added all the no.,which are formed by interchanging the digits of each of the given no.surprisingly,the sum he got was the same as the sum the teacher has asked for.which of the following is the difference of the digits in the least of the no. the student was asked to add? a) 2 b) 3 c)4d) 5
When we have to take ten different sets of 2 digit no, where difference between them is 10, then it will be like ( 11,21,31...91) or (13,23,33,43,..93) and so on.
So unit digit will be same.
Tens digit will increse by 1, starting from 1 and ending at 9.
Suppose, x is unit digit.
Then nos are 1x,2x,3x.....9x
Sum is 10*(1+2+3..+9) +9x
= 450+9x........Eq 1
Nos chosen by student
x1,x2...x9
Sum = 10*9x +(1+2+3....+9)
= 90X+45........Eq 2
Now Eq1=Eq2
450+9x=90x+45
81x = 405
x = 5
Now first original no is 1x......ie 15.
So positive difference is 5-1 = 4
So unit digit will be same.
Tens digit will increse by 1, starting from 1 and ending at 9.
Suppose, x is unit digit.
Then nos are 1x,2x,3x.....9x
Sum is 10*(1+2+3..+9) +9x
= 450+9x........Eq 1
Nos chosen by student
x1,x2...x9
Sum = 10*9x +(1+2+3....+9)
= 90X+45........Eq 2
Now Eq1=Eq2
450+9x=90x+45
81x = 405
x = 5
Now first original no is 1x......ie 15.
So positive difference is 5-1 = 4
the cost of digging a pit was Ra 1347.how much will it cost if the wages of workmen per day had been increased by 1/8 of the former wages and length of the working day increased by 1/20 of the former period?
a 1439 b 1234 c 1000 d none
please suggest.
how to approach by percentage method or other
@IIM-A2013 said:the cost of digging a pit was Ra 1347.how much will it cost if the wages of workmen per day had been increased by 1/8 of the former wages and length of the working day increased by 1/20 of the former period?a 1439 b 1234 c 1000 d noneplease suggest.how to approach by percentage method or other
1347*9/8*20/21=1443.2
d. none?
d. none?
Let wage initially be x,
so now wage is= 9/8 x....(i)
Let initially no. of days = D
and in each day no of working hours= m,
now no of working hours = 21/20 m,,,
hence no of days in which work will be completed = 20/21 D......(ii)
so total cost = 1347 x(9/8 x (20/21)
( as wage increases so total cost increases, days decreases, wage also decreases)= 1443.214
DS Question:
Is ˆš(x-3) ˛ = (3-x)
1. x is not equal to 3
2. -x|x| > 0
Is ˆš(x-3) ˛ = (3-x)
1. x is not equal to 3
2. -x|x| > 0
Can someone also explain how to solve the equation given to find values of x
Let g(y) = p*y^2 + q*y + r, where p,q,r are constants, p not equal to 0, and 3*g(8) = -4*g(2). The roots of g(y)=0 are 6 and m. Find m.
@joyjitpal said:Let g(y) = p*y^2 + q*y + r, where p,q,r are constants, p not equal to 0, and 3*g(8) = -4*g(2). The roots of g(y)=0 are 6 and m. Find m.
192p+24q+3r+16p+8q+4r=0
=> 208p+32q+7r=0
and 36p+6q+r=0 => 252p+42q+7r=0
==> 44p+10q=0
==> q=-44/10p
==> r=-36p+264/10p=-96/10p
m^2p+mq+r=0
==> m^2-44/10m-96/10=0
==> 10m^2-44m-96=0
==> 5m^2-22m-48=0
==> m=6 or -8/5
-8/5
=> 208p+32q+7r=0
and 36p+6q+r=0 => 252p+42q+7r=0
==> 44p+10q=0
==> q=-44/10p
==> r=-36p+264/10p=-96/10p
m^2p+mq+r=0
==> m^2-44/10m-96/10=0
==> 10m^2-44m-96=0
==> 5m^2-22m-48=0
==> m=6 or -8/5
-8/5
@IIM-A2013 said:@krum ans is right please tell me this step1347*9/8*20/21=1443.2
cost is directly related to wage and inversely related to work hour, just use this and multiply the right factors
if a and b are positive integers then ˆš2 always lies between :
1 a and b
2 a/b and (a+2b)/(a+b)
3 (a+b)/(a-b) and ab
4 ab/(a+b) and (a-b)/ab
@IIM-A2013 said:if a and b are positive integers then ˆš2 always lies between :1 a and b2 a/b and (a+2b)/(a+b)3 (a+b)/(a-b) and ab4 ab/(a+b) and (a-b)/ab
2?