maths
posted by arshad on .
a man started to play a card game .in the first round he doubled the amount and he gave away a certain amount say P to his friend.In the second round,he tripled the amount left with him after the first round and gavew away an amount 2P to his friends.in the third round he quadrupled the amount left with him after the second round and gave away an amount P to his friend and was finally left with no money.if he gave away a total of RS.160 to his friend,then what was the money left with him?

let the amount he started with be x
after first round he has 2xP
in 2nd round he tripled that and gave away 2P
so has left
6x  3P  2P = 6x  5P
in 3rd round he quadrupled the amount and gave away P
so he has left
24x  20P  P = 24x  21P
amount given away = P + 2P + P = 160
P = 40
but at the end he has nothing left, so
24x  21P = 0
24x  21(40) = 0
x = 35
He started with RS 35
check:
in first round: doubled , gave away P
7040 = 30
in 2nd round: tripled, gave away 2P
90  80 = 10
in 3rd round: quadrupled , gave away P
40  40 = 0
my solution checks out.