Answer:
266
Explanation:
Let the attendence of 5days be a,b,c,d,e
given,
(a+b+c+d+e)/5=264
a+b+c+d+256=264*5 [since 5th day=256]
(a+b+c+d+)/4=1(320-256)/4 [dividing both side by 4]
average attendence of 4 days =266
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