Question

ans is 10 come fast ​

Answer 1

Nope, answer is not 10 mate...

Answer 2

$\Large\tt{||\:GIVEN\:||}$

Neela saves in a Mahila Bachat Gat Rs.5 on the first day, Rs.7 on the second day, Rs.9 on the third day and so on.

$\Large\tt{||\:TO\:FIND\:||}$

Neela's saving in the month of August.

$\Large\tt{||\:SOLUTION\:||}$

✇ As per the given data we will get a sequence of the form 5, 7, 9, . . . which forms an arithmetic progession.

Here,

⦾ The first day saving is taken as, a = 5

⦾ Second day saving is taken as, a₁ = 7

⦾ The difference in saving is taken as d

$;\implies\:\tt{d\:=\:a_1\:-\:a}$

$;\implies\:\tt{d\:=\:7\:-\:5}$

$;\implies\:\bf{d\:=\:2}$

Here,

⦾ Here n is the number of days.

We know that,

⦾ There are 31 days in August.

Therefore,

n = 31

✇ So, to calculate the savings in the month of August we have to consider the following formula :

$\orange\star\:{\underline{\boxed{\bf{\purple{S_n\:=\:\dfrac{n}{2}\:\Big[2a\:+\:(n\:-\:1)\:d\Big]}}}}}\:\green\star$

$\hookrightarrow\:\tt{S_n\:=\:\dfrac{31}{2}\:\Big[2\times{5}\:+\:(31\:-\:1)\:2\Big]}$

$\hookrightarrow\:\tt{S_n\:=\:\dfrac{31}{2}\:\Big[10\:+\:30\times{2}\Big]}$

$\hookrightarrow\:\tt{S_n\:=\:\dfrac{31}{2}\:[10\:+\:60]}$

$\hookrightarrow\:\tt{S_n\:=\:\dfrac{31}{2}\times{70}}$

$\hookrightarrow\:\tt{S_n\:=\:31\times{35}}$

$\hookrightarrow\:\bf\pink{S_n\:=\:1085}$

$\Large\bf{Therefore,}$

The savings in the month of August is Rs.1085.