Question

Kunal wants to spend his money. So he was going out from his home for some shopping.
And suddenly kunal stopped and prayed to god that if my money will be double I will donate 20 rupees in the temple.
And after few minutes his money doubled and he donated 20 rupees in the temple.
kunal did same this atleast three times from the starting.
But at fourth time. kunal didnt had any money left.

Now answer how much money kunal had when he was going out from his home...

Answer 1

2[2[2x-20]-20]-20=0

[2[2x-20]-20=10

2[2x-20]=30

2x=35

x=17.5

Answer 2

let the intail amount =x
so according to first time=2x-20=y_____(1)
second time =2y-20=z_______(2)
third time =2z-20=0
2z=20
z=20÷2=10
putting value of z in eq 2
2y-20=10
2y=10+20=30
y=30÷2=15
putting this in eq 1
2x-20=15
2x=15+20=35
x=35÷2=17.5 answer