At least five wisk is weight of the produce of the crops over which Zakat becomes obligatory. Five wisk is equal to____?

At least five wisk is weight of the produce of the crops over which Zakat becomes obligatory. Five wisk is equal to____?

کم از کم پانچ وسک فصلوں کی پیداوار کا وزن ہے جس پر زکوٰۃ واجب ہو جاتی ہے۔ پانچ وِسک ____ کے برابر ہے؟
Explanation

wisk is equal to 40kg

zakat became obligatory on 2nd hijri