Find the Ju2a From your pocket money, you save 1 on day 1, 2 on day 2,

1.	Find the Ju2a From your pocket money, you save 1 on day 1, 2 on day 2, 3 on day 3 and so o[CBSE 2007 (How much money will you save in the month of March 2008? [CBSE 2008 (S
Answer» As it is given in question.. Saving is Rupee 1 On 1st day,2 rupees on 2nd day and 3 rupees on 3rd day and so on.. Clearly, it forms an A. P 1,2,3.....31. (as last day of march is 31 st) So, a = 1 ,d =2-1 =1. Last term (ań)=31 S31= n/2[2a+(n-1)d] S31=31/2[21+(31-1)1 S31=31/2[2+30] S31=3116 S31=496 U save rupees 496 in march 2008

Find the Ju2a From your pocket money, you save 1 on day 1, 2 on day 2, 3 on day 3 and so o[CBSE 2007 (How much money will you save in the month of March 2008? [CBSE 2008 (S

Answer»

As it is given in question.. Saving is Rupee 1 On 1st day,2 rupees on 2nd day and 3 rupees on 3rd day and so on..

Clearly, it forms an A. P

1,2,3.....31. (as last day of march is 31 st)

So, a = 1 ,d =2-1

=1.

Last term (ań)=31

S31= n/2[2a+(n-1)d]

S31=31/2[2*1+(31-1)1

S31=31/2[2+30]

S31=31*16

S31=496

U save rupees 496 in march 2008