11th Class
Mathematics
Sample Paper
Maths Olympiad Model Paper-8
question_answer
A person is to count 4500 currency notes. Let \[{{a}_{n}}\]denotes the number of notes he counts in the nth minute. If \[{{a}_{1}}={{a}_{2}}=.....={{a}_{10}}=150\] and \[{{a}_{10}},\] \[{{a}_{11}}.....\] are in AP with common difference \[-\,2,\]then the time taken by him to count all notes, is