How many baby dinosaurs and adult dinosaurs were there?

Question

Each baby dinosaur made 15 paintings and each adult dinosaur made 7 paintings. The entire herd of dinosaurs made 208 paintings in total, and there were 3 times as many baby dinosaurs as adult dinosaurs. How many baby dinosaurs and adult dinosaurs were there?

Answer 1

15B + 7A = 208

B=3A

15(3A) +7A = 208

45A + 7A = 208

52A = 208

A =208/52=4 adults

B= 3(4) = 12 babies

15(12) + 7(4)= 180+28 = 208