A man deposited $Rs$ $10000$ in a bank at the rate of $5 \%$ simple interest annually. Find the amount in $15^{\text {th }}$ year since he deposited the amount and also calculate the total amount after $20$ years.
It is given that the man deposited $Rs.$ $10000$ in a bank at the rate of $5 \%$ simple interest annually.
$=\frac{5}{100} \times Rs .10000= Rs .500$
$\therefore$ Interest in first year $10000+\underbrace{500+500+\ldots+500}_{14 \text { times }}$
Amount in $15^{\text {th }}$ year
$= Rs . 10000+14 \times Rs .500$
$= Rs .10000+ Rs .7000$
$= Rs .17000$
Amount after $20$ years $= Rs .10000+\underbrace{500+500+\ldots+500}_{20 \text { times }}$
$= Rs .10000+20 \times Rs .500$
$= Rs .10000+ Rs .10000$
$=R s .20000$
Let $a_1 , a_2, a_3, .... , a_n$, be in $A.P$. If $a_3 + a_7 + a_{11} + a_{15} = 72$ , then the sum of its first $17$ terms is equal to
If $a,b,c,d,e$ are in $A.P.$ then the value of $a + b + 4c$ $ - 4d + e$ in terms of $a$, if possible is
If $A$ be an arithmetic mean between two numbers and $S$ be the sum of $n$ arithmetic means between the same numbers, then
If $(b+c),(c+a),(a+b)$ are in $H.P$ , then $a^2,b^2,c^2$ are in.......
Let $l_1, l_2, \ldots, l_{100}$ be consecutive terms of an arithmetic progression with common difference $d_1$, and let $w_1, w_2, \ldots, w_{100}$ be consecutive terms of another arithmetic progression with common difference $d_2$, where $d_1 d_2=10$. For each $i=1,2, \ldots, 100$, let $R_i$ be a rectangle with length $l_i$, width $w_i$ and area $A_i$. If $A_{51}-A_{50}=1000$, then the value of $A_{100}-A_{90}$ is. . . . .