GWD 09-33

[briandragon]

Q33:
Working simultaneously and independently at an identical constant rate, 4 machines of a certain type can produce a total of x units of product P in 6 days. How many of these machines, working simultaneously and independently at this constant rate, can produce a total of 3x units of product P in 4 days?

A. 24
B. 18
C. 16
D. 12
E. 8

答案是B
可以請高手解題ㄧ下嗎~~?

[65kevin]

由題目可知, 四台機器一天可以生產 P 產品 x/6 unit, 所以用 3x/4 (即每一天要生產 3x/4 unit, 才可以達到要求) 去除以 x/6 , (3x/4)/(x/6) = 4.5, 所以所需的機器數量是 4 * 4.5 = 18 , Ans is (B)

[briandragon]

感謝