Answer:
![n(A)=38](https://tex.z-dn.net/?f=n%28A%29%3D38)
Step-by-step explanation:
In sets theory n(A) represents the number of elements in set A.This number is the cardinal number of the set A.
For n(AUB) there is an equation that relates n(A),n(B) and n(A∩B) :
n(AUB) = n(A) + n(B) - n(A∩B)
In our exercise :
n(AUB) = n(A) + n(B) - n(A∩B)
![59 = n(A) +38-17\\n(A) = 59-38+17\\\\n(A)= 38](https://tex.z-dn.net/?f=59%20%3D%20n%28A%29%20%2B38-17%5C%5Cn%28A%29%20%3D%2059-38%2B17%5C%5C%5C%5Cn%28A%29%3D%2038)
Another important equation for maths is similar to this one :
P(AUB) = P(A) + P(B) - P(A∩B)
Where ''P'' is the event probability.This equation is used in probability and statistics.
Answer:
Jose is 54years Rachael is 38years
Step-by-step explanation:
Jose=x-12
Rachael=x-12/2
sum of their ages x-12+x-12/2=63
collect like terms
x=54years
Jose =54years
Rachael=38years
Answer:
2) First option
3) Second option
Step-by-step explanation:
5² = 625
13 × 8 × 5 = 520
Answer: 83.33% decrease
<u>Step-by-step explanation:</u>
![\frac{New - Original}{Original}](https://tex.z-dn.net/?f=%5Cfrac%7BNew%20-%20Original%7D%7BOriginal%7D)
![\frac{0.5 - 3}{3}](https://tex.z-dn.net/?f=%5Cfrac%7B0.5%20-%203%7D%7B3%7D)
= ![\frac{-2.5}{3}](https://tex.z-dn.net/?f=%5Cfrac%7B-2.5%7D%7B3%7D)
= -0.8333
= -83.33%