49. A child puts one five-rupee coin of her savings in the piggy bank

1.	49. A child puts one five-rupee coin of her savings in the piggy bank on thefirst day. She increases her saving by one five-rupee coin daily. If thepiggy bank can hold 190 coins of five rupees in all, find the number ofdays she can contribute to put the five-rupee coins into it and find theICBSE 2017)total money she saved
Answer» Money added to money bank on first day = rs 5 on second day = rs 10 0n third day = rs 15 and so on n = 190 thus AP = 5, 10. 15, ...........195 thus a =5 d =5 n= 190 Thus S = n/2[2a+(n-1)d] = 95[ 10 + 189*5] = 90725 thus total money is 90725 Rs wrong solution

49. A child puts one five-rupee coin of her savings in the piggy bank on thefirst day. She increases her saving by one five-rupee coin daily. If thepiggy bank can hold 190 coins of five rupees in all, find the number ofdays she can contribute to put the five-rupee coins into it and find theICBSE 2017)total money she saved

Answer»

Money added to money bank on first day = rs 5 on second day = rs 10 0n third day = rs 15

and so on n = 190

thus

AP = 5, 10. 15, ...........195

thus a =5 d =5 n= 190

Thus S = n/2[2a+(n-1)d] = 95[ 10 + 189*5] = 90725

thus total money is 90725 Rs

wrong solution