If n(a)=40,n(b)=60 and n(a∪b)=80.find the value of (a∩b.

20

Step-by-step explanation:

we know,

n(aUb)=n(a)+n(b)-n(a∩b)

so,

80=40+60-n(a∩b)

or, 80-(40+60)=-n(a∩b)

or, -n(a∩b)=80-100

or, -n(a∩b)=-20

or, n(a∩b)=20

x is the total time in minutes for the free response

you are given number of questions as 15 - m and time per item as 8 minutes

to find x multiply the two givens together:

x = 8 * (15-m) = 8(15-m)

answer: the angel abc is 30°,and the abc is a triangle where the angel bac is 90°

so ac is the half of 24=12ft,and from the pythagorean theorem we find ba

ba=√bc^2-ac^2=√576-144=√432=12√3ft

so bac is 12+12√3=12(1+√3)ft