11th Class
Mathematics
Sample Paper
Maths Olympiad Model Paper-5
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