Question

URL
If n (AX B) = 15, n (A) = 3 then n (B) is
A
12
SECARE
ES
.
B
5
c
45
D
3​

Answer 1

Answer

Option B) 5

$\rule{200}1$

Explanation

Given,

n(A × B) = 15

n(A) = 3

To find n(B)

If a set P has p elements and another set Q has q elements, then the number of elements in (P × Q) is pq, that is, n(P) × n(Q) = n(P × Q).

Thus,

n(A) × n(B) = n(A × B)

→ 3 × n(B) = 15

→ n(B) = 5

Hence, set B has 5 elements.

Answer 2

ANSWER :-

Given :-

• n(A×B) = 15

• n(A) = 3

Find :-

• n(B) = ?

Calculation :-

=> n(A) × n(B) = n(A×B) ---------(formula)

•put values

=> .°. 3 × n (B) = 15

=> .°. n(B) = 15/3

=> .°. n(B) = 5

therefore, set B has 5 elements.

=> .°.option b)5.

☆VERICATION :-

=> n(A) × n(B) = n(A×B)

=> 3 × 5 = 15

=> 15 = 15

• hence verified!!