# Aptitude - Simple Interest - Discussion

### Discussion :: Simple Interest - Data Sufficiency 2 (Q.No.1)

Each of the questions given below consists of a question followed by three statements. You have to study the question and the statements and decide which of the statement(s) is/are necessary to answer the question.

1.

 What is the principal sum? I. The sum amounts to Rs. 690 in 3 years at S.I. II. The sum amounts to Rs. 750 in 5 years at S.I. III. The rate of interest is 5% p.a.

 [A]. I and III only [B]. II and III only [C]. I and II only [D]. I and III only, or II and III only [E]. Any two of the three

Explanation:

Clearly, any two of the three will give us the answer. Correct answer is (E).

 Moncy Kurien said: (Sep 27, 2010) We can find the principal amount by using the options I and II. But how can we find the principal amount using either I and III or II and III? Please explain.

 Abcd said: (Jan 26, 2011) P + P.3.r% = 690---(1) P + P.5.r% = 750---(2) divide eqn 1 by 2 to get r and then p.

 Udit Chauhan said: (Feb 4, 2011) Excellent abcd!!

 Akshaya said: (Feb 11, 2011) Hi Abcd, Using II & III p+((p*5*5)/100)=750 .....(1) Solving (1),we get p=600. Similarly,we can do with I & III

 Pooja said: (Aug 16, 2013) Please explain how p+(p*5*5/100) get?

 Aman said: (Dec 3, 2013) According to third equation rate of interest is 5% so putting that in second equation that is p + p*rate*time/100 = sum. p + p*5*5/100 = 750.

 Chaud said: (Sep 4, 2014) P + P.3.r% = 690---(1). P + P.5.r% = 750---(2). Divide eqn 1 by 2 to get r and then p. Please explain how to divide 1 by 2 to get r and then p?

 Sam said: (Sep 27, 2014) Please explain how to get the answer from using only III?

 Srira said: (Oct 6, 2014) Please explain the formula of this question and give me some easy way.

 Anandhi D said: (Nov 6, 2014) I cannot understand Please explain the formula of this question and give me some easy way.

 Dass said: (Dec 9, 2014) What is the basic formula for the sum?

 9E Tej said: (Jan 10, 2015) Somebody please explain.

 Manju said: (Jun 7, 2015) Help needed in understanding division of equations!

 Ashis said: (Jun 21, 2015) In very simple level I explain to 9 how to get answer using ll & similarly only from (ll) we get P+S.I = 750 & T = 5. And from (lll) we get R = 5. Now P+(P*5*5)\100 = 750. 100P+25P = 750*100. 125P = 75000. P = 600.

 Qwers said: (Aug 1, 2015) There wasn't any information given with r% in the question (statements 1, 2). So I don't think taking are in both the cases is correct. So option D should be correct clarify.

 Ashish said: (Aug 2, 2015) For those who need help regarding how to divide equation I and II (as suggested by abcd). 750 = P+(P*R*5)/100 => 75000 = 100P + 5PR. (i). 690 = P+(P*R*3)/100 => 69000 = 100P + 3PR. (ii). Subtracting (i) & (ii) , we get. R = 3000/P. Now substitute it in any one either (i) or (ii) , we get. P = 600. Thanks.

 Scientist said: (Aug 30, 2015) We can find answer using I and II as follows:. 5PR% = 750 - P. 3PR% = 690 - P --- Dividing them. ---------------. 5 750-P. = 3 690-P. 3450 - 5P = 2250 - 3P. 1200 = 2P. P = 600. Using I and III. I = PNR%.

 Aman Kumar Shaw said: (Mar 8, 2016) How can we get the answer by using I and II. Please tell?

 Aryan said: (Jun 29, 2016) I. Amount after 3 years = 690. II. Amount after 5 years = 750. Difference = SI for 2 years = 60. SI for 1 year = 30, SI for 3 years = 90, SI for 5 years = 150, Thus, Principal = 600.

 Kishor said: (Jul 8, 2016) Please explain that how to get the answer from eq 1 & 2 only.

 Vickma said: (Aug 11, 2016) AMOUNT = S. I + P. 690 - P = 3PR -> (1). 750 - P = 5PR -> (2). Divide Eqn 2 by 1; P = 600. Use P = 600 in section I & III. So, the correct option is 'E'.

 Girish said: (Aug 26, 2016) 690 - P = 3PR. 750 - p = 5PR. Dividing both equations (690 - P)/(750 - P) = 3/5. -> (690 - P)5 = (750 - P)3. By solving; P = 600.

 Shruthi said: (Aug 31, 2017) If it is any two of the 3 then there is a possibility of taking 1 and 2. How can we get p using 1 and 2?

 P V Snehil said: (Sep 11, 2017) We cannot get P using I and II, as we donot know the are when we have only these two statements. Correct answer is D.

 Mansi Arora said: (Dec 31, 2017) Hi @Aryan, We are using here all the three given statements to get the value of P which is not given in the options.

 Effoti said: (Mar 20, 2018) By using I and II; S.I for 2 years = 750-690 = 60 as S.I is divided uniformly for each year, For 1 year = Rs. 30 and For 3 year = 90, Principal = 690-90 = 600. By using II and III As Total Sum = Principal + Interest i.e 750 = P + I (after 5 years) ------> (1) P = I *100 / R * T = I *100 / 5*5 = 4I, Put value of P in eq. 1, 750 = 5I , I = 150 and P = 750 -150 = Rs. 600, Similarly By using I and III. P = I *100 / R*T = I*100/5*3 = 20/3(I), 690 = 20/3(I) + I , By solving this we get I = Rs.90 and P = 690 - 90 = Rs. 600. Hence answer is E Any two of the three.