word problem

konan wrote:Mark bought shares of a particular stock for a total value of $1000. Next day, the price of shares is reduced by 10%. With the same $1000, he could now buy 10 more shares. Which of the following is closest to the original price per share? please help me with this....

Some answer choices would be helpful

Algebraically, we can call the initial price 'p' and the initial number of shares 'q.' So p*q = 1000, or p =1000/q

If the price is reduced by 10%, the new price would be .9p. If he can buy 10 more shares, he can now afford q + 10 shares. So (.9p)(q+10) = 1000; Simplifying, we get .9pq + 9p = 1000. If, using our initial equation we substitute 1000/q in place of p, we'll have:
.9q(1000/q) + 9p = 1000
900 + 9p = 1000
9p = 100
p = 100/9 = 11.11111

So... whichever answer choice is closest to 11.11 would be your answer.