Aptitude - Decimal Fraction - Discussion
Discussion Forum : Decimal Fraction - General Questions (Q.No. 12)
12.
| 4.2 x 4.2 - 1.9 x 1.9 | is equal to: |
| 2.3 x 6.1 |
Answer: Option
Explanation:
| Given Expression = | (a2 - b2) | = | (a2 - b2) | = 1. |
| (a + b)(a - b) | (a2 - b2) |
Discussion:
14 comments Page 1 of 2.
Bittu Rana said:
2 months ago
(4.2-1.9)(4.2+1.9)/2.3*6.1.
So, the Answer: B 1.0
So, the Answer: B 1.0
Aakash gk said:
4 years ago
Neeraj just take the approx value;
For eg;
4.2 as 4,
1.93 as 2,
2.3 as 2,
6. 1 as 6.
You'll 4 * 4 - 2*2 / 2*6.
= 12/12,
= 1.
For eg;
4.2 as 4,
1.93 as 2,
2.3 as 2,
6. 1 as 6.
You'll 4 * 4 - 2*2 / 2*6.
= 12/12,
= 1.
(19)
Neeraj Bhaskar said:
5 years ago
How the denominator value is match with the mentioned formula? please explain.
(1)
Murali said:
5 years ago
I have taken approx value of;
4.2 as 5
1.9 as 2
2.3 as 3
and 6.1 as 7.
and I got the answer 1.
4.2 as 5
1.9 as 2
2.3 as 3
and 6.1 as 7.
and I got the answer 1.
(1)
Mohan bhuyan said:
5 years ago
Thanks all for explaining the answer.
(1)
Shubh said:
7 years ago
Nice & clear explanation. Thanks @Arvind.
Arvind_ap said:
1 decade ago
Its simply.
4.1 x 4.1 = 17.64 & 1.9 x 1.9 = 3.61.
Now 17.64 - 3.61 = 14.03.
= 2.3 x 6.1 = 14.03.
So 14.03/14.03.
Answer = 1.
4.1 x 4.1 = 17.64 & 1.9 x 1.9 = 3.61.
Now 17.64 - 3.61 = 14.03.
= 2.3 x 6.1 = 14.03.
So 14.03/14.03.
Answer = 1.
(4)
Harish said:
1 decade ago
Just simply subtract 4.2-1.9 = 6.1 and add 4.2+1.9 = 2.3.
You can easily find logic.
You can easily find logic.
(1)
Prasad said:
1 decade ago
But how to think that much logically?
Raju trimukhe said:
1 decade ago
Use formula a^2-b^2 = (a+b)(a-b).
(4.2+1.9)(4.2-1.9) = (6.1)(2.3).
Whole expression:
= (6.1)(2.3)/(6.1)(2.3).
= 1.
(4.2+1.9)(4.2-1.9) = (6.1)(2.3).
Whole expression:
= (6.1)(2.3)/(6.1)(2.3).
= 1.
(5)
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