### Discussion :: Compound Interest - General Questions (Q.No.5)

Chaitu said: (Nov 23, 2010) | |

30000(107/100)=32100 (32100*7)/100=147 is for 1 year 2100+2100+147=4347 2 years |

Lalitha said: (Mar 25, 2011) | |

Can any one please help how it has come (107/100)^2 |

Dittya said: (Apr 5, 2011) | |

Yaa, its because (107)^2 = 11449 and (100)^2 = 10000. |

Prabakaran said: (Jul 19, 2011) | |

What is 107/100 ? |

Anusha said: (Oct 16, 2011) | |

Amount=30000+4347 = 34347 amount=p(1+R/100)^n 34347=30000(1+7/100)^n 34347=30000(107/100)^n 34347/30000=(107/100)^n 11429/10000=(107/100)^n. hence (107/100)^2=11429/10000. |

Mercy said: (Jan 20, 2012) | |

Simpler yet old-fashioned solution to me would be: 30000*7/100=2100 - year 1 30000+2100=32100*7/100=2247 - year 2 now add 2100+2247=4347 which was the compound interest earned after 2years. Thus the ans is 2 years. |

Swa1 said: (Aug 22, 2012) | |

4347=30,000(1+7/100)^n why not? and 30,000+4347=34,347 why? plz any one explian me. |

Usha said: (Sep 14, 2013) | |

C.I will be the 4347. C.I = AMOUNT-PRINCIPAL. PRINCIPAL = 30,000. 4347 = AMOUNT-30000. AMOUNT = 4347+30000 = 34347. AMOUNT = P(1+R/100)^n. 34347 = 30000(1+7/100)^n. 34347/30000 = (107/100)^n. |

Sumit P. said: (Oct 25, 2013) | |

Sorry Guys but it should; 11449 / 10000 // 34347 / 30000 is multiplied and divide by 3. Hence, Now 11449 and 10000 are squares of 107 and 100 resp. Thus(107 / 100)^ 2. Thus n = 2. |

Anshu said: (Dec 20, 2013) | |

30000*7/100 = 2100 - year 1. 30000+2100 = 32100*7/100 = 2247 - year 2. Now add 2100+2247 = 4347 which is 2 years. |

Hafsa Ali said: (Jan 2, 2014) | |

Why we add 30,000 and 4347? |

Arpita Dey said: (Feb 26, 2014) | |

How (107/100)^t = 34347/30000. t=2? I forgot the conversion. |

Manasa said: (Mar 7, 2014) | |

What is the shortcut method for calculating the square root of 11449? |

Fizna said: (Nov 19, 2014) | |

Can anyone say the exact formula for finding the period? |

Hitendra said: (Dec 2, 2014) | |

How to calculate (107/100)^t = 34347/30000? |

Rajnish said: (Dec 11, 2014) | |

Hi guys, I think (107/100)^t is not easy to find without using calculator. So, I want advice you play hit and trial. Take t = 1, t = 2, ..... and match your option. |

Tejas said: (Dec 15, 2014) | |

Why 34347/30000? |

Digvijay said: (Dec 18, 2014) | |

Ya! it's not easy to find out. We have to try with value of t. |

Isha Sharma said: (May 9, 2015) | |

Guys this is simple divide numerator and denominator by 3 you will get your answer. |

Trilok said: (Sep 14, 2015) | |

11449/10000 = (107/100)^n , 1.1442 = (1.07)^n. We can write as log 1.1442 = n log 1.07, n = log 1.1442/log 1.07 = 0.058501/0.029383 = 2 (as per scientific calculator). |

Bhabani said: (Oct 20, 2015) | |

A sum becomes double in ten years in C.I. So in how many years the principal would be 8 times? |

Leo said: (Nov 28, 2015) | |

Can anyone explain me the simplification of (107/100)2? |

Abhilok said: (Dec 6, 2015) | |

2 times in 10 years. 2^3 = 8 times in 3*10 = 30 years. Let power = n. Given year = y. n*y is the answer. |

Dearlie Beloved said: (Dec 30, 2015) | |

Shortcut through using ln: t = ln (34 347/30 000)/ln (1.07). t = 2 years. |

Anurag Nath said: (May 12, 2016) | |

@Hitendra. (107/100)n = 11449/10000. => 107 * 107/100 * 100 = 11449/10000. => (107/100)2 = 11449/10000 [Here n = 2]. Therefore n=2. |

France said: (Jun 28, 2016) | |

107 * 107 is 11449 and 100 * 100 = 10000 but how is it equal to 34347/30000 ? |

Rkh said: (Nov 14, 2016) | |

What if the power is( 107/100)^4?. How can we find quad root of a number? |

Chloe said: (Mar 27, 2017) | |

Use the formula n = [ log(fv/p) ] / [ log (1+i)]. Where FV = future value. P = present value. i = interest ( in dec. place). n = [ log ( 34,347/30,000) ] / [ log (1+0.07)]. = 2. |

B. Tatung said: (May 9, 2017) | |

How come 3 divided by both numerator and denominator? Please, someone, explain me. |

Akash Kumar Sinha said: (Jul 14, 2017) | |

1st year CI= 7% OF 30000 ie 2100. 2nd year CI=2100+ 7% of 2100 ie 147. 2100+2100+147=4347. Hence, 2 years. |

Priya said: (Jul 29, 2017) | |

What is 107/100? I can't understand, please explain. |

Shipra said: (Aug 2, 2017) | |

Thanks people. It helped a lot! |

Subramanyam said: (Aug 23, 2017) | |

Thanks, friends. It helped a lot! |

Narsim Bari said: (Feb 27, 2018) | |

30000*7/100 = 2100 for 1rst year. For 2nd year : 30000+2100*7/100 = 2247. Now, cross-check the given calculated amount given in the question itself i.e 4347 rupees by adding 2 years amount (2100+2247)=4347. Believe this is the fastest and tricky method of our natural mind. |

Prasad said: (Jun 15, 2018) | |

Why we square that 107/100 n=2? why? please. |

Sangavi said: (Dec 9, 2018) | |

Why we add 30000 and 4347, can anyone please explain it? |

Bimla Jarmwal said: (Jan 4, 2019) | |

Please, anyone, explain the answer in detail to me. |

Anomie said: (Jan 29, 2019) | |

How did come 11449? |

Lokesh said: (Mar 21, 2019) | |

Verify with given option. CI =7 % 1ST YEAR 7%. For 2nd year, it becomes 7.49 Total 14.49 If 100% = 30K. Then 114.49 = ? (114.49 * 30K)รท100. And you will get 4347. |

Migma Tshering Tamang said: (Oct 12, 2020) | |

34347=30000(1+0.07)^n. 1.1449=(1.07)^n. Using log in both the side. log1.1449=n * log1.07. n=log1.1449/log1.07. n=2 years. |

Saron said: (Oct 25, 2021) | |

Very good, Thanks everyone for explaining. |

Garima said: (Dec 9, 2021) | |

Can anyone please tell me how (1+7/100) become (107+100)? |

Nitish said: (May 2, 2022) | |

No @Garima. You should write it as 107/100 which came by the basic addition method. |

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