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At what rate (in percentage) per annum will тВ╣1,300 give тВ╣520 as simple interest in 5 years?
4%
5%
7%
8%
8%
Calculate the total simple interest as a percentage of the principal: (520├╖1300)├Ч100=40%. Since this interest is earned over 5 years, divide by 5 to get the annual rate: 40%├╖5=8%.
Principal (P) = тВ╣1,300, Simple Interest (SI) = тВ╣520, Time (T) = 5 years
R=P├ЧTSI├Ч100тАЛ
Calculate the total simple interest as a percentage of the principal: (520├╖1300)├Ч100=40%. Since this interest is earned over 5 years, divide by 5 to get the annual rate: 40%├╖5=8%.
Multiplying the principal with time incorrectly or dividing the total interest directly without considering the number of years.
Identify the given values from the question
We are given the Principal amount P=тВ╣1,300, the Simple Interest SI=тВ╣520, and the Time period T=5┬аyears.
P=1300,SI=520,T=5
State the standard formula for Rate of Interest
The formula for calculating the rate of interest (R) per annum in simple interest is derived from SI=100P├ЧR├ЧTтАЛ. Rearranging for R gives: R=P├ЧTSI├Ч100тАЛ
R=P├ЧTSI├Ч100тАЛ
Substitute the values into the formula
Substitute SI=520, P=1300, and T=5 into the rate equation: R=1300├Ч5520├Ч100тАЛ
R=1300├Ч5520├Ч100тАЛ
Perform the calculation
Simplify the numerator and the denominator: R=650052000тАЛ=65520тАЛ=8%
R=8%
D is correct because substituting the given values into the simple interest formula yields a rate of 8% per annum.
Always verify simple interest problems by recalculating the interest using the derived rate to ensure SI=100P├ЧR├ЧTтАЛ matches the given interest.