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

Answer 1

15b + 7a = 208

b = 3a

 

Substitute!

 

15(3a) + 7a = 208

 

Solve for a and plug your answer into the 2nd equation to find b.