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**A boy agrees to work at the rate of one rupee on the first day, two rupees on the second day, and four rupees on third day and so on. How much will the boy get if he started working on the 1st of February and finishes on the 20th of February?**

A. $2^{20}$
B. $2^{20}-1$
C. $2^{19}-1$
D. $2^{19}$
**Answer: Option B**

## Show Answer

Solution(By Apex Team)

$\begin{array}{l}1^{\text{st }}\text{ term }=1\\
\text{ Common ration }=2\\
Sum\left(S_n\right)=a\times\frac{r^n-1}{r-1}\\
\qquad\begin{aligned}&=1\times\frac{2^{20}-1}{2-1}\\
&=2^{20}-1\end{aligned}\end{array}$

## Related Questions On Progressions

### How many terms are there in 20, 25, 30 . . . . . . 140?

A. 22B. 25

C. 23

D. 24

### Find the first term of an AP whose 8th and 12th terms are respectively 39 and 59.

A. 5B. 6

C. 4

D. 3

### Find the 15th term of the sequence 20, 15, 10 . . .

A. -45B. -55

C. -50

D. 0

### The sum of the first 16 terms of an AP whose first term and third term are 5 and 15 respectively is

A. 600B. 765

C. 640

D. 680