Question

Find the amount on Rs. 12,000 in 3 years, when the rates of interest for
successive years are 8%, 10%, 12% respectively.​

Answer 1

➤ Answer (1) :-

Principle :- ₹ 12000

Rate of interest :- 8%

Time :- 3 years

Total Amount :-

${\tt \longrightarrow \bigg( \dfrac{12000 \times 8 \times 3}{100} \bigg) + 12000}$

${\tt \longrightarrow \dfrac{\cancel{12000} \times 8 \times 3}{\cancel{100}} = \boxed{\tt 120 \times 8 \times 3}}$

${\tt \longrightarrow 120 \times 24 = Rs \: \: 2880}$

${\tt \longrightarrow 2800 + 12000}$

${\tt \longrightarrow \boxed{\tt Rs \: \: 14880}}$

➤ Answer (2) :-

Principle :- ₹ 12000

Rate of interest :- 10%

Time :- 3 years

Total Amount :-

${\tt \longrightarrow \bigg( \dfrac{12000 \times 10 \times 3}{100} \bigg) + 12000}$

${\tt \longrightarrow \dfrac{\cancel{12000} \times 10 \times 3}{\cancel{100}} = \boxed{\tt 120 \times 10 \times 3}}$

${\tt \longrightarrow 120 \times 30 = Rs \: \: 3600}$

${\tt \longrightarrow 3600 + 12000}$

${\tt \longrightarrow \boxed{\tt Rs \: \: 15600}}$

➤ Answer (3) :-

Principle :- ₹ 12000

Rate of interest :- 12%

Time :- 3 years

Total Amount :-

${\tt \longrightarrow \bigg( \dfrac{12000 \times 12 \times 3}{100} \bigg) + 12000}$

${\tt \longrightarrow \dfrac{\cancel{12000} \times 12 \times 3}{\cancel{100}} = \boxed{\tt 120 \times 12 \times 3}}$

${\tt \longrightarrow 120 \times 36 = Rs \: \: 4320}$

${\tt \longrightarrow 4320 + 12000}$

${\tt \longrightarrow \boxed{\tt Rs \: \: 16320}}$

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$\dashrightarrow$ Formula used :-

Total amount :- ${\boxed{\tt\dfrac{P \times R \times T}{100} + Principle}}$

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$\dashrightarrow$ Some related formulas :-

Simple Interest :- ${\boxed{\tt\dfrac{P \times R \times T}{100}}}$

Principle :- ${\boxed{\tt\dfrac{SI \times 100}{R \times T}}}$

Rate of interest :- ${\boxed{\tt\dfrac{SI \times 100}{P \times T}}}$

Time :- ${\boxed{\tt\dfrac{SI \times 100}{P \times R}}}$