Question

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Sarah Purchases every year National Saving Certificates of value exceeding the last year purchases by Rs.25. After 20 years, she find the total value of certificates purchased by her is Rs.7250. Find the value of the certificates purchased.​

Answer 1

Answer:

${\huge{\boxed{\red{\mathscr{SolutioN}}}}}$

Common Difference = ₹500

S₆ = ₹13,500

Sn = n/2 {2a+(n-d)d}

13,500 = 6/2 { 2a + (6-1)500}

13,500/3 = 2a + (5×500)

2a = 4,500 - 2,500

2a = 2000

a = 1000

a = 1000,d = 500

The required AP is 1000,1500,2000,2500,3000,3500.....

So , the value of the certificates purchased in 5th year is ₹3000 .

Answer 2

Step-by-step explanation:

{\huge{\boxed{\red{\mathscr{SolutioN}}}}}

SolutioN

Common Difference = ₹500

S₆ = ₹13,500

Sn = n/2 {2a+(n-d)d}

13,500 = 6/2 { 2a + (6-1)500}

13,500/3 = 2a + (5×500)

2a = 4,500 - 2,500

2a = 2000

a = 1000

a = 1000,d = 500

The required AP is 1000,1500,2000,2500,3000,3500.....

So , the value of the certificates purchased in 5th year is ₹3000 .