व्याकरण — Sanskrit STD 12 Science — Question

Arya' is 'matramel' metre (based on short and long vowles). In this type of metre number of letters or their long and short form is not fixed. But the number of mantras is fixed / definite. (number of mantras counted for short is one and for 'guru' i.e. long is two) The characteristic of this metre is given as under.
    यस्याः प्रथमे पादे द्वादशमात्राः तथा तृतीयेऽपि ।
    अष्टादश द्वितीये चतुर्थके पञ्चदश साऽऽर्या ॥
It means when there are twelve 'matras' in the first and the third quarter of a stanza, and fifteen 'mantras' in the second and the fourth quarter of a stanger the metre is "Arya'.
Illustration:
   व्यसने मित्रपरीक्षा शूरपरीक्षा रणाङ्गणे भवति ।
    विनये भृत्यपरीक्षा दानपरीक्षा च दुर्भिक्षे ॥
(Meaning: Friend is tested in the time of crisis.Braveman is tested on a battlefield, Servant is tested in politness and charity / donation is tested in the time of famine)
    In the first quarter there are twelve 'mantras' like  व्य (1) स (1) ने (2) मि (2) त्र (1) प (1) री (2) क्षा (2) thus there are twelve 'mantras'. In the second quarter are शू (2) र (1) प (1) री (2) क्षा (2) र (1) णा (2) ङ्ग (1) णे (2) भ (1) व (1) ति (2) totally 18 mantras. In the third quarter there are वि (1) न (1) ये (2) भृ (2) त्य (1) प (1) री (2) क्षा (2) twelve mantras and in the fourth quarter there are दा (2) न (1) प (1) री (2) क्षा (2) च (1) दु (2) भि (2) क्षे (2) 15 mantras. Sol there is Arya metre (used) in this stanza.