Question

16. In what time will 1860 amount to 2348.25, if
simple interest is calculated at 7 whole 1/2% per annum.
​

Answer 1

Given :-  

Principal = ₹1860

Amount = ₹2348.25

Rate =  7 1/2 %  

To Find :-  

The time period

Solution :-

We know that,    

${\sf{S.I\:=\:{\dfrac{P\:\times\:R\:\times\:T}{100}}}}$

On inserting the values in the formula

We get ,    

${\sf{S.I\:=\:{\dfrac{1860\:\times\:T\: \times\:15}{100\:\times\:2}}}}$

${\sf{\implies\:S.I\:=\:{\dfrac{93\:\times\:T\:\times\:3}{2}}}}$

${\sf{\implies\:S.I\:=\:{\dfrac{279T}{2}}}}$

Now,

Amount = Principal + Interest

= 1860 + ${\sf{{\dfrac{279T}{2}}}}$

But also given that Amount is 2348.25

Therefore,

According to question,

${\sf{1860\: +\: {\dfrac{279T}{2}}\: =\:2348.25}}$

${\sf{\implies\: {\dfrac{279T}{2}}\: =\: 2348.25\:-\:1860}}$

${\sf{\implies\: {\dfrac{279T}{2}}\: =\:488.25}}$

${\sf{\implies\:T\: =\: {\dfrac{488.25\: \times\: 2}{279}}}}$

${\sf{\implies\:T\: =\:3.5}}$

Therefore, time period is 3.5 years