$1.$ What will the following program display on the screen?

#include

Using namespace std;

class Tank

$\{$

private:

$$ int gallons;

public:

$$ Tank$()$

$\{$ gallons $=50$; $\}$

$$ Tank$($int gal$)$

$\{$ gallons $=$ gal; $\}$

$$ int getGallons$()$

$\{$ return gallons; $\}$

$\}$;

int main$()$

$\{$

$$ Tank storage$[3]=\{10,20\}$;

$$ for $($int index $=0$; index $<3$; index$++)$

$$ cout $<<$ storage$[$index$].$getGallons$()<<$ endl;

$$ return $0$;

$\}$