Forum:Phineas and Ferb's Age...

Let's get straight to the point:

In Phineas and Ferb: Quantum Boogaloo, Linda  stated that Phineas and Ferb are 30 years old in the future. Does this mean that the boys are 10 years old when the series began? Their wiki pages state that they're at least 15...

PS: also, how was Candace's age identified? Her age was not mentioned in Candace's Big Day...