Question

a sum amounts to ₹4680 in 4 years at 5% per annum, then the sum is?
[ANSWER WITH FULL PROCESS]
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Answer 1

Answer:

3900

Step-by-step explanation:

4680 = principal + interest = amount

we know,

amount = principal × (1+rate×time)

4680 = principal × (1+5/100×4)

4680 = principal × 6/5

4680 ÷ 6/5 = 4680 × 5/6 = principal

3900 = principal amount

780 = interest

Answer 2

The sum is ₹ 3900

Given :

A sum amounts to ₹ 4680 in 4 years at 5% per annum

To find :

The sum

Solution :

Step 1 of 2 :

Form the equation

Let the sum = ₹ P

Time = T = 4 years

Rate of interest = R% = 5%

Then interest

$\displaystyle \sf{ = \frac{PRT}{100} }$

$\displaystyle \sf{ = \frac{P \times 4 \times 5}{100} }$

$\displaystyle \sf{ = \frac{20P }{100} }$

$\displaystyle \sf{ = \frac{P }{5} }$

Amount

$\displaystyle \sf{ = P + \frac{P }{5} }$

$\displaystyle \sf{ = \frac{6P }{5} }$

By the given condition

$\displaystyle \sf{ \frac{6P }{5} = 4680 }$

Step 2 of 2 :

Find the sum

$\displaystyle \sf{ \frac{6P }{5} = 4680 }$

$\displaystyle \sf{ \implies P = 4680 \times \frac{5}{6} }$

$\displaystyle \sf{ \implies P = 3900}$

The sum is ₹ 3900