$($a$)$ All the waters are not fit for irrigating crops. Discuss briefly and critically this statement. $7$

$($b$)$ What is meant by 'Duty' and 'Delta' of canal water? Derive a relationship between duty and delta for a given base period. $705777$

$($c$)$ Find the delta for sugarcane when its duty is $730$ hectares$/$cumec on the field and the base period of the crop being $110$ days.

$2$