Question

why they take rs 1.75 as an why they dont take it as sn?????

Answer 1

In the question , it is asked that what will the saving become .

It is not asked that what amount he has saved.

His weekly saving was 5 in first week.

Then it become 5 +1.75=6.75 , so his saving is 6.75 in second week , means , in first week , he was saving rs 5 everyday , then he increased his saving by 1.75 and saved 6.75 rs everyday .

So we have to find that in which week he is saving 20.75 per day.

so a1=5rs

a2=6.75

a3=8.5

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an=20.75