I believe the last answer would be correct.
I have 81¥ and I'm going to the US, so I need to convert my Yen into US Dollars, if i get 1 USD (US Dollar) for every 9¥, how many USD will i have if i convert all of my Yen?
Answer:
a = 6, b = 22.5
Step-by-step explanation:
One triangle is 2.5 times bigger than the other.
9*2.5=22.5 which means b = 22.5
15/2.5=6 which means a = 6