Aptitude - Decimal Fraction - Discussion
Discussion Forum : Decimal Fraction - General Questions (Q.No. 8)
8.
The expression (11.98 x 11.98 + 11.98 x x + 0.02 x 0.02) will be a perfect square for x equal to:
Answer: Option
Explanation:
Given expression = (11.98)2 + (0.02)2 + 11.98 x x.
For the given expression to be a perfect square, we must have
11.98 x x = 2 x 11.98 x 0.02 or x = 0.04
Discussion:
27 comments Page 1 of 3.
Nandaraj said:
1 decade ago
We know that.
(a + b) ^2 = a^2 + b^2 + 2ab.
Here a = 11.98.
b = 0.02.
2ab = 11.98x.
Therefore,
x = 2ab/11.98.
= (2*11.98*0.02) / 11.98 (11.98 cancel each other).
= 2*0.02.
x = 0.04.
(a + b) ^2 = a^2 + b^2 + 2ab.
Here a = 11.98.
b = 0.02.
2ab = 11.98x.
Therefore,
x = 2ab/11.98.
= (2*11.98*0.02) / 11.98 (11.98 cancel each other).
= 2*0.02.
x = 0.04.
(28)
Vanaja said:
1 year ago
=> (11.98)^2 + (0.02)^2 + 11.98 * x.
=>11.98*x = 2 * 11.98 * 0.02.
=>11.98*x = 0.04 * 11.98.
X = 0.04 * 11.98/11.98.
X = 0.04.
=>11.98*x = 2 * 11.98 * 0.02.
=>11.98*x = 0.04 * 11.98.
X = 0.04 * 11.98/11.98.
X = 0.04.
(8)
JSubba said:
7 years ago
Simple explanation.
For it to be a perfect square it should be like this: a^2 + 2ab + b^2 So what's missing in that equation to be a perfect square is 2b so here b is 0.02 so 2*0.02 = 0.04.
For it to be a perfect square it should be like this: a^2 + 2ab + b^2 So what's missing in that equation to be a perfect square is 2b so here b is 0.02 so 2*0.02 = 0.04.
(6)
Sachin said:
3 years ago
@Nandaraj.
If we take b= 0. 2 then x = 0. 4, that will also be an answer.
If we take b= 0. 2 then x = 0. 4, that will also be an answer.
(4)
Shweta said:
5 years ago
I think the ans should be 0.2.
(11.98)^2+2*11.98*0.02 +(0.02)^2.
2*0.02= 0.04=x^2.
x=0.2.
(11.98)^2+2*11.98*0.02 +(0.02)^2.
2*0.02= 0.04=x^2.
x=0.2.
(3)
Abhilash said:
5 years ago
Compare with [ (a+b) ^2 ] formula.
(3)
Supriyo Ghosh said:
3 years ago
Well explained, Thanks @Nandaraj.
(1)
Ssundaram said:
8 years ago
Thanks for the detailed explanation @Tushar, @Ram, @Nandaraj.
Ivan said:
3 years ago
Thanks for explaining @Nandaraj.
Jaanu Jaanu said:
3 years ago
Thanks for the clear explanation @Nandaraj.
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