Practice 3 A target practice weapon can fire a maximum of X rounds per minute. It takes roughly R seconds to fully assemble and R seconds to reload. Ammunition is distributed by the case. Each case contains 18, 000 rounds. In terms of the variables X, F, and R, select the expression that represents the number of rounds used in 1 hour of practice, when the weapon is used to its maximum capacity, and select the expression that represents the number of shooting practice hours that a full case of ammunition can cover. Make only two selections, one in each column.
正确答案:
The correct answers are 60Xrounds used in 1 hour and practice hours covered by a full case. 该武器每分钟最多能发射x次,1小时有60分钟,因此该武器1小时能发射60次。 一个盒子里有18000子弹,射击训练1小时会用掉60x发子弹,由此可知1盒子弹可用于射击的时间为18000/60x。