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May 17th, 2018, 03:17 AM   #1
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Where am I going wrong?

Anoop deposited a certain amount at 15% p.a simple interest in the name of his son when his son was 6 years old. It became 37,240/- when his son turned 12 years of age. What was the amount he deposited initially?

Ans) R = 15%

I = 37240

T = 6 years

SI = P * R * T/ 100

37240 = (P * 15 * 6 )/ 100

P = 37240 * 100/15 * 6

P = 41377.7

But answer is 19,600. How?
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May 17th, 2018, 05:27 AM   #2
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Quote:
Originally Posted by Ganesh Ujwal View Post
37240 = (P * 15 * 6 )/ 100
Should be: 37240 = P + (P * 15 * 6)/100
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June 19th, 2018, 08:39 AM   #3
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Let the amount originally deposited be A. Then 15% for 6 years would be 90%. It will have earned 0.9A interest so the total will be A+ 0.9A= (1.9)A= 37240. A= 37240/1.9= 19600.

You calculated A so that the interest alone would be 37240, not the total amount: 41377.7*.9= 37240.
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June 19th, 2018, 12:02 PM   #4
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The given answer assumes that Anoop made the deposit described when his son turned six years old, not simply "when his son was six years old".
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