Question

What sum will amount to Rs. 900 in 6 years at 10% simple interest?

Answer 1

$\underline\textbf{Solution}$

Given,

• Amount = Rs.900
• Time = 6 years
• Rate = 10%

Find,

• Sum/Principal = ?

Solution,

→ $\bf{Let\:principal\:to\:be\:x}$

→$s.i \: = \: \frac{p \times r \times t}{100} \\→ s.i \: = \: \frac{10 \times x \times 6}{100} \\ →s.i \: = \: \frac{6}{10}x \\→ s .i \: = \: \frac{3}{5} x$

Amount = Principal + Simple interest

$900 = \frac{x}{1} + \frac{3x}{5} \\</strong><strong>→</strong><strong> 900 = \frac{5x + 3x}{5} \\ </strong><strong>→</strong><strong>900 = \frac{8x}{5} \\</strong><strong>→</strong><strong> 900 \times 5 = 8x \\ </strong><strong>→</strong><strong>4500 = 8x \\ </strong><strong>→</strong><strong>\frac{4500}{8} = x \\ </strong><strong>→</strong><strong> \frac{1125}{2} = x \\</strong><strong>→</strong><strong> 562.5 = x$

→ So,we've got the value of principal. It is x = 562.5.

$\huge\underline\textbf{Important\:Formulas}$

• S.I = P × R × T/100
• Amount = Principal + Simple interest

Thank You!!

Answer 2

Answer:

562.5 is the value of x ( principle )