First, let's find the number of people rather than percentages.
65% of 600 is 390.
49% of 600 is 294
7% of 600 is 42.
The total amount of people that use the facilities is 600 - 42 = 558.
To find the number of people who use both, we add the two together and then subtract the actual amount of people, or 600.
390 + 294 = 684
684 - 600 = 84.
To find the probability, divide it by 600 to get 84/600 = 42/300 = 21/150 = 7/50.
Ok, so if it ends with a zero, that means it is divisible by ten. This means the number is divisible by both 5 and 2.
The sum of the digits is also divisible by 3, so that means it is divisible by 3.
Because it is divisible by 3 and 2, it is also divisible by 6.
6, 3, 5, 2, are the only ones that can necessarily divide it, so your answer is 4.
Let X be the starting weight of the grapefruit, which is 100 pounds. Let W be the amount of water evaporated. Let the amount of water at start be A. 92% of X is A, and 90% of X-W is A - W. Equation is 23X/25 = A, 9(X-W) /10 = A - W. The first equation is 23X = 25A, the second is expanded into 9X-9W = 10A - 10W, or 9X + W = 10A. Remember that we want to find X - W, so we substitute A for X using the first equation. (5/2)(9X + W) =23X.
45X/2 + 5W/2 = 23X. 45X + 5W = 46X. X = 5W. We know X was 100, so 5W = 100, or W = 20. Thus, the final answer is 100-20 = 80. We can check the answer by seeing 90% of 80 is 9/10 * 80 = 72, which is 20 less than 92% of the start.