Interest at the time of maturity
\[=\text{ }Rs.\text{ }1200\]
Period (x)
\[~=\text{ }2\text{ }years\]
\[=\text{ }24\text{ }months\]
Rate of interest
\[=\text{ }6%\text{ }p.a.\]
Consider Rs. P p.m. as the monthly deposit
Since,
Interest
\[=\text{ }P\text{ }\times \text{ }\left[ x\text{ }\left( x\text{ }+\text{ }1 \right) \right]/\text{ }\left( 2\text{ }\times \text{ }12 \right)\text{ }\times \text{ }r/100\]
Putting the value of x
\[1200\text{ }=\text{ }\left( P\text{ }\times \text{ }24\text{ }\times \text{ }25 \right)/\text{ }24\text{ }\times \text{ }6/100\]
Or,
1200 = 6/4P
By cross multiplication
\[P\text{ }=\text{ }\left( 1200\text{ }\times \text{ }4 \right)/\text{ }6\]
\[=\text{ }800\]
Here monthly deposit
\[=\text{ }Rs.\text{ }800\]
So the amount of maturity
\[~=\text{ }P\text{ }\times \text{ }x\text{ }+\text{ }SI\]
\[=\text{ }800\text{ }\times \text{ }24\text{ }+\text{ }1200\]
\[=\text{ }19200\text{ }+\text{ }1200\]
\[=\text{ }Rs.\text{ }20400\]