Answer to Question #94018 in Real Analysis for Daniel

Question

5.Let S = {a, b, c, d} and T = {f, b, d, g}. Then the intersection of set S and T is
a.{b, d, f}
b.{b, d}
c.{b, d,c}
d.{b, d, g}

6.The … are those real numbers, which can be expressed as the ratio of two integers
a.natural numbers
b.irrational numbers
c.rational numbers
d.integers

Answer 1

5. 

By definition: 

In mathematics, the intersection A∩B of two sets A and B is the set that contains all elements of A that also belong to B 

(or equivalently, all elements of B that also belong to A), but no other elements.

Taking the above into consideration sets, 

S∩T = {b, d}.

Answer: b.{b, d}

More info on the topic: https://en.wikipedia.org/wiki/Intersection_(set_theory)

6. 

By definition, 

In mathematics, a rational number is any number that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q.

Answer: c.rational numbers

More info on the topic: https://en.wikipedia.org/wiki/Rational_number