Elitmus
Exam
Numerical Ability
Arithmetic
Sum of two number is 1000 and the sum of their recipocal is 2/255.Let the smallest of 2 number be L, so which of the following is correct value range for L?
a)0
Read Solution (Total 6)
-
- As per the question , let the smaller number be L and larger number be H.
So, L+H = 1000..........eqn 1
And
1/L+1/H= 2/255
(L+H)/LH = 2/255
LH = (L+H)*255/2
LH= 127500.................eqn 2
Now,
(H-L)^2 =(H+L)^2 - 4HL
(H-L)^2 = 1000000-4*127500
= 1000000-510000
=490000
Now,
(H-L) =sqrt(490000)
= 700
H-L=700...............................eqn 3
From eqn 1 and 3
L=150
H=850
- 9 years agoHelpfull: Yes(17) No(0)
- Ans =150
the process used is same as explained in other solution. - 9 years agoHelpfull: Yes(2) No(0)
- 17
- 9 years agoHelpfull: Yes(1) No(2)
- on solving quadratic equation y^2-1000y+127500
we get two roots 150 and 850
smaller one is 150. - 9 years agoHelpfull: Yes(1) No(0)
- Ans should be = 75
x+y=1000 so, y=1000-x
1/x + 1/y = 2/255
now replace 1/y with 1/(1000-x), and solve ::::
Lastly we get using discriminant method x= 1000 + or - sqt{(1000^2) -4*127500}
on solving we have to take minimum value so we'll use - not +
so small number will be 75.
So ans=75 - 9 years agoHelpfull: Yes(0) No(2)
- as per today's eLitmus exam 19/07/2015 options are
(1) 0 - 9 years agoHelpfull: Yes(0) No(0)
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