Answer:
The total amount of students in the primary school is 1,980.
Explanation:
130, 210, 290, ......
210 - 130 = 80
The difference between each grade is 80 students.
(g = grade)
g1 = 130, g2 = 210, g3 = 290, g4 = 370, g5 = 450, g6 = 530
130+210+290+370+450+530 = 1980