A man saved ₹660000 in 20 years.

Solution:

Given: -

Amount saved by a man in 20 years is Rs.660000

Let the amount saved by him in the first year be $a$.

In every succeeding year, he saves Rs.2000 more than what he saved in the previous year.

Increment of saving of the year when compared last year is Rs. 2000

Hint: - The above information looks like the savings are in Arithmetic Progression.

Amount saved in first year $=\mathrm{a}$

Common difference $=\mathrm{d}=₹ 2000$

Total number of years $=\mathrm{n}=20$

The total amount saved in 20 years is $₹ 660000$

Sum of $n$ terms in an A.P $=\frac{n}{2}[2 \times a+(n-1) \times d]$

$660000=\frac{20}{2}[2 \times a+(20-1) \times 2000]$

a = 14000

∴ In the first year, he saved ₹14000.