An item originally priced at $200 is discounted three separate times, each time by 10% off the current price. What is the final price?

Each discount takes $10\%$ off the current price, so multiply by $0.9$ three times: $200(0.9)=180$, then $180(0.9)=162$, then $162(0.9)=145.80$. The final price is $145.80, choice B. Equivalently, $200(0.9)^3=200(0.729)=145.80$. Choice A ($140) treats the three discounts as a single $30\%$ discount, which ignores that each discount is on a smaller amount. Choice D ($162) applies only two discounts. Choice C ($150) is a rough guess. Successive percent discounts are multiplied, not added.