How much was his capital at the begining according to the optinal question?

Question

A businessman promised that he would give $5 for each time if he can get profit respectively 25%, 50% and 100%. But at last he found that he had no money. How much was his capital?

Answer 1

Working backwards. On the last day the man had a certain amount of money (x) and he got 100% gain and gave away $5. But when he gave away the $5 he had no money left.
(x + 100%) - $5 = 0
x + 100% = $5
x = $ 2.50 (because x itself is 100%).

So the man would have had $ 2.50 on the second last day.
(x + 50%) - $5 = $ 2.50
x + 50% = $7.50
x = $5.00

So the man would have had $ 7.50 on the third last day.
(x + 25%) - $5 = $ 5.00
x + 25% = $ 10.00
x = $8.00

So the man had $8.00 to begin with.

Answer 2

Let's work backward.

After a 100% profit and giving $5 away he is left with zero dollars. Thus, before the 100% profit he must have had $2.50.

$2.50 + (100% of $2.50) - $5 = 0

After a 50% profit and giving $5 away he is left with $2.50. Thus, before the 50% profit he must have had $5.

$5 + (50% of $5) - $5 = $2.50

After a 25% profit and giving $5 away he is left with $5. Thus, before the 25% profit he must have had $8.

$8 + (25% of $8) - $5 = $5.

ANSWER: He began with $8

Answer 3

well if he had no money i guess it was free