LIVE Course for free

Rated by 1 million+ students
Get app now
0 votes
10 views
in Aptitude by (54.3k points)
closed by
Sunder Pichai CEO of Google invested certain amount of money at the rate of 5% per annum compound interest, the interest compounded annually. If the difference between the interests of third year and first year is $307.50. Find the amount of money he invested.
1. $ 50,000
2. $ 40,000
3. $ 60,000
4. $ 80,000

1 Answer

0 votes
by (30.0k points)
selected by
 
Best answer
Correct Answer - Option 3 : $ 60,000

Given

Rate of Internet = 5%

Difference between the interest of third year and first year = $ 307.50

Formula Used

S.I. = PRT/100

A = P(1 + R/100)n

Calculation∶

Let the sum of money be invested be $x

Rate of interest = 5% p.a.

Now,

Interest for the first year = (x × 5 × 1) / 100 = $ x/20

Interest for the 3rd year i.e. the C.I. for the third year = amount after 3 years - amount after 2 years.

C.I. for the 3rd year = x(1 + 5/100)3 - x(1 + 5/100)2 

⇒ x[(21/20)3- (21/20)2]

⇒ [x × (21/20)2(21/20 - 1)]

⇒ x ×  441/400 × 1/20

⇒ $ 441x/8000

Given, difference between interests of third year and first year is Rs.307.50

441x/8000 - x/20 = 307.50 = 615/2

⇒ (441 - 400)x/8000 = 615/2

⇒ 41x/8000 = 615/2

⇒ x = 615/2 × 8000/41 = $ 60,000

∴ The sum of money invested by Sunder Pichai is $60,000.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...