Question

An A.P 5, 12, 19 --- Has 60 Terms
its Last term Hence. Find the sum
of its first 15 term.​

Answer 1

Answer:

sorry that is right answer

I hope it's help you

Answer 2

Answer:

810

Step-by-step explanation:

we have a=5

c.d = 12-5=7

n=15

we know formula for sum

$S_{n}=\frac{n}{2}[2a+(n-1)d]\\ \\S_{15}=\frac{15}{2}[2*5+(15-1)7]\\\\S_{15}=\frac{15*108 }{2}\\\\S_{15}=810\\\\Hope \ it \ is \ clear \ to \ you$