In a group of 200 high school students, 36 are taking biology, 52 are taking spanish, and 126 are taking neither biology nor spanish. if one of these 200 students is to be chosen at random, what is the probability that the student chosen is taking biology but not spanish?
a. 7%
b. 11%
c. 18%
d. 37%

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally