Answer
If 93 is last term of $b_{n}$ then there are 19 terms in $b_{n}$.
= 19 terms
Work Step by Step
From graph
First term $b_{1}$ = 3
Second term $b_{2}$ = 8
Third term $b_{3}$ = 13
Sequence = 1, 8, 13, . . . . .
Common difference (d) = 13 - 8 = 8 - 3 = 5
Given Last term ($b_{L}$)= 93
Number of terms = $\frac{Last term - first term }{d}$ + 1
= $\frac{b_{L} - b_{1}}{d}$ + 1
= $\frac{93 - 3}{5}$ + 1
= $\frac{90}{5}$ + 1
= 18 + 1
= 19
If 93 is last term of $b_{n}$ then there are 19 terms in $b_{n}$.