Convert 2/5 to a decimal and you get .4, or 40%. 40% of the band members also sing, so yes, the band has the same number of string instrument players and singers.
Answer:
-675
Step-by-step explanation:
The sum can be broken into parts that you know. Here, one of those parts is the sum of numbers 1 to n. That sum is given by n(n+1)/2.

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Another way to do this is to realize the sequence of numbers is an arithmetic sequence with a first term of 65 and a last term of 67-2·75 = -83.
The sum of an arithmetic sequence is found by multiplying the number of terms by their average value. Their average value is the average of the first and last terms.
The average value of those 75 terms is (65 +(-83))/2 = -9, so their sum is ...
75(-9) = -675
Answer:
The probability that the town has 30 or fewer residents with the illness = 0.00052.
Step-by-step explanation:
So, we have the following set of data or information or parameters given from the question above and they are; the number of people living in that particular society/community/town = 74,000 residents and the proportion of people that the diseases affected = .000215.
The first step to do is to determine the expected number of people with disease. Thus, the expected number of people with disease = 74,000 × .000215 = 15.91.
Hence, the probability that the town has 30 or fewer residents with the illness = 1.23 × 10^-7 × 15.91^30/ 2.65253 × 10^-32 = 0.00052.
Note the formula used in the calculating the probability that the town has 30 or fewer residents with the illness = e^-λ × λ^x/ x!
All you have to do is divide the ounces he has into how much he gives the dog each day so 128/8 is 16