Elitmus
Exam
Numerical Ability
Number System
The sum of two numbers is 15 and their geometric mean is 20% lower than their arithmetic mean.Find the numbers.
(a)11,4 (b)12,3 (c)13,2 (d)10,5
Read Solution (Total 14)
-
- By the help of option 12,3 is right answer because
12+3=15
gm of 12,3=6
am of 12,3 =7.5
20% of am=1.5
hence gm is 20% lower than am.
so, it satisfy the whole condition.
- 9 years agoHelpfull: Yes(15) No(1)
- ans: 12,3
the arithmetic mean is (12+3)/2 = 7.5
the geometric mean is sqrt(12*3)=6
the 20% of arithmetci mean is 1.5
therefore geometric mean is 20% less than the arithmetic mean - 9 years agoHelpfull: Yes(7) No(0)
- answer is b i.e. 12,3
- 9 years agoHelpfull: Yes(3) No(6)
- X+Y=15
SQRT(xy) =.8((X+Y)/2)
XY=36 using both eqn ans is 12,3 - 9 years agoHelpfull: Yes(1) No(0)
- correct answer is 12,3
EXPLANATION:
consider two number a and b
if we check option 2
a =12 b=3
a+b=12+3=15
arithmetic mean =a+b/2
12+3/2=15/2=7.5
geometric mean =root(a*b)
=root(36)=6
accon to question geometric mean is 20 % less than aritmetic
so 7.5*80/100=6
- 8 years agoHelpfull: Yes(1) No(0)
- correct ans= b(12,3)
- 7 years agoHelpfull: Yes(1) No(0)
- let us assume 2 no. x and y
AM=(x+y)/2
GM^2=xy
x+y=15(given
Am=15/2=7.5
Gm=Am-20% of AM
=7.5- (20*7.5/100)
=7.5-1.5=6
Gm=6;
Gm^2=36
xy=36
x+y=15;
solving both we get x=12 and y=3 - 6 years agoHelpfull: Yes(1) No(0)
- correct answer is b 12,3 . direct arun sharma book question
- 8 years agoHelpfull: Yes(0) No(1)
- correct answer is b 12,3 . direct arun sharma book question
- 8 years agoHelpfull: Yes(0) No(0)
- correct answer is b 12,3 . direct arun sharma book question
- 8 years agoHelpfull: Yes(0) No(0)
- correct answer is b 12,3 . direct arun sharma book question
- 8 years agoHelpfull: Yes(0) No(0)
- correct answer is b 12,3 . direct arun sharma book question
- 8 years agoHelpfull: Yes(0) No(0)
- go through the option consider option(b)
gm of 12,3=sqrt of(12,3)=6
am of 12,3=(12+3)/2=7.5
20%of am=1.5
gm=7.5-1.5=6 - 7 years agoHelpfull: Yes(0) No(0)
- let, 1st no=a then 2nd no=15-a
power 1/2 of a(15-a)=15/2-15/2*20%
by solving we get a=12 ,3 and b=3,12 - 6 years agoHelpfull: Yes(0) No(0)
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