A bank pays interest to its customers on the last day of the year. The interest paid to a customer
is calculated as 10% of the average monthly balance maintained by the customer. John is a customer at the bank. On the last day, when the interest was accumulated into his account, his bank balance doubled to $7540. What is the average monthly balance maintained by John in his account during the year?  Choose the correct choice from the following answers.
A) 2840	B) 5680	C) 6840	D) 7540	E) 37700
Soln:-   Bank balance is doubled with accumulation of interest to 7540..   this means INTEREST is   7540/2= 
<gadget id="calculator">  7540/2</gadget>
<output>3_770</output>
3770 for entire year..   although since interest is 10% of avg MONthly balance, it becomes 37700..   ANSW37700R:37700
<result>E</result>
A bank pays interest to its customers on the last day of the year. The interest paid to a customer
is calculated as 10% of the average monthly balance maintained by the customer. John is a customer at the bank. On the last day, when the interest was accumulated into his account, his bank balance doubled to $7540. What is the average monthly balance maintained by John in his account during the year?