Question

if =A={8,10,12,14,16,18,20} find n(A)​

Answer 1

Answer:

$n=7$

Step-by-step explanation

∴$d=a_{2} -a_1\\d=10-8\\d=2$

∴ $a=8\\l=20$

∴$n=(\frac{l-a}{d} )+1$

$n=(\frac{20-8}{2})+1$

$n=(\frac{12}{2} )+1$

$n=6+1$

$n=7$