If the simple interest on Rs. 2000 is less than the Simple Interest on Rs. 3000 at 5% by Rs. 50, find the time.
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Solution 1
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$\dfrac{3000 \times 5 \times \text{T}}{100} - \dfrac{2000 \times 5 \times \text{T}}{100} = 50$
$\left(3000-2000\right)\dfrac{5 \times \text{T}}{100} = 50$
$1000 \times \dfrac{5 \times \text{T}}{100} = 50$
$50 \text{T} = 50$
$\text{T} = 1\text{ year}$
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Solution 2
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Difference in principal = $\left(3000-2000\right)$ = 1000
i.e., Simple Interest on Rs.1000 will be Rs.50
$\dfrac{1000 \times 5 \times \text{T}}{100} = 50$
$50 \text{T} = 50$
$\text{T} = 1\text{ year}$