Kanika was given her pocket money on 1st Jan 2016 .she puts ₹1 on day 1,₹ 2on day 2 and ₹ 3 on day 3 and continued on doing so till the end of the month ,from this money into her piggy bank. She also spent ₹204 of her pocket money and was found that at end of the month she still has ₹100 with her . How much money  was her pocket money for the month?

Asked by Anmolrishiket | 30th Jan, 2019, 12:27: PM

Expert Answer:

According to teh question the series is
1, 2, 3, 4, .....31
a = 1, d = 1
Sn = n/2 (a + tn)
S31 = 31/2 (1 + 31)
S31 = 496
Piggy bank contains Rs. 496.
Let the pocket money has Rs. x. She spent Rs. 204, Remaining amount = Rs. 100
x - 496 - 204 = 100 
x = 800 
Kanika received Rs. 800 as pocket money.

Answered by Sneha shidid | 30th Jan, 2019, 01:46: PM