# Aptitude - Decimal Fraction - Discussion

### Discussion :: Decimal Fraction - General Questions (Q.No.1)

1.

 Evaluate : (2.39)2 - (1.61)2 2.39 - 1.61

 [A]. 2 [B]. 4 [C]. 6 [D]. 8

Explanation:

 Given Expression = a2 - b2 = (a + b)(a - b) = (a + b) = (2.39 + 1.61) = 4. a - b (a - b)

 Danny Sawkmie said: (Sep 10, 2011) Iven Expression = a2 - b2 = (a + b)(a - b) = (a + b) = (2.39 + 1.61) = 4. a - b (a - b) Explain clearly

 Aptitute said: (Sep 20, 2014) Given Expression = a^2 - b^2 = (a + b)(a - b). (a^2 - b^2)/(a - b) = (a + b) = (2.39 + 1.61) = 4.

 Mary Grace said: (Dec 14, 2014) Can you explain this clearly? Please.

 Praveen Kumar said: (Jun 7, 2015) 2.39*2.39 = 5.7121. 1.61*1.61 = 2.6565. 2.39-1.61 = 0.78. Its nothing 5.7121-2.6565/0.78 = 4.

 Manas Kumar Patra said: (Jun 23, 2015) Can you explain how (a+b)(a-b)/(a-b)=a+b?

 Suni said: (Dec 27, 2015) (a+b)(a-b)/(a-b), its simple division where a-b gets cancelled an that = a+b.

 Franky said: (May 22, 2016) This is easy, just (a + b)(a - b)/(a - b). Then just by cancelling the both minus and remaining a+b is the answer. Formula : (a^2) - (b^2) = (a + b)(a - b)/a - b. Enter the amount: (2.39 + 1.61)(2.39 - 1.61)/2.39 - 1.69). Cancel both 2.39 - 1.61)/(2.39 - 1.69). Then remaining in the numerator is 2.39 + 1.61 = 4. So, the answer is 4.

 Sabit said: (Sep 8, 2016) How did the 2nd step come?

 Mahesh said: (Apr 29, 2017) Good explanations, Thank you all.

 Sindhu said: (May 4, 2017) Not getting this. Please Explain me clearly.

 Ashwani said: (Mar 18, 2018) Here the formula of a2-b2 = (a+b)(a-b). so (a+b)(a-b)/(a-b) here both (a-b) are canceled, so (a+b) is reminder here a= 2.39 & b= 1.61, then 2.39+1.61=4 .

 Rajeswari said: (Apr 1, 2018) Not getting this, please explain clearly.

 Lalita said: (Sep 7, 2018) Please explain it again.

 Kato Ballack Godfrey said: (Nov 16, 2018) Explain how?

 Mr.Soumya Dhwaj said: (May 25, 2019) See what we have to do is, (a+b)x(a-b)/(a-b). (2.39+1.61)x(2.39-1.61) divided by/(2.39-1.61). Solving them by opening the brackets we get, 4x0.78/0.78. Now by solving it we get a figure =3.12 divided by/0.78. Finally, we get = 4 as our answer.