Answer:
a) 21, 24, 29
b) 5 terms in the sequence are less than 50
Step-by-step explanation:
[tex]t_n = n^2+20\\t_1 = 1^2+20 = 1+20= 21\\t_2 = 2^2+20 = 4+20= 24\\t_3 = 3^2+20 = 9+20= 29\\\\\\t_5 = 5^2+20 = 25+20= 45\\\\\\t_6 = 6^2+20 = 36+20= 56\\[/tex]
Since, 5th term is less than 50 and 6th term exceeds 50, therefore 5 terms in the sequence are less than 50.