1. Please solve these questions.
The cost C of manufacturing a certain product can be estimated by the formula C = 0.03rst^2, where r and s are the amounts, in pounds, of the two major ingredients and t is the production time, in hour. If r is increased by 50%, s is increased by 20%, and t is decreased by 3.0%, by approximately what percent will the estimated cost of manufacturing the product change?
2. In a certain deck of cards, each card has a positive integer written on it. In a multiplication game, a child draws a card and multiplies the integer on the card by the next larger integer. If each possible product is between 15 and 200, then the least and greatest integers on the card could be --- (a) 3 and 15 (b) 4 and 13
(c) 4 and 14