A boy has Rs. 640 in the denominations of one-rupee notes, five-rupee notes and ten-rupee notes. The number of notes of each denomination is equal. What is the total number of notes that he has ?  Choose the most appropriate option:
A) 90
B) 110
C) 140
D) 130
E) 120
Let number of notes of each denomination be x.   Then x + 5x + 10x = 640   16x = 640   x = 40.   Hence, total number of notes = 3x = 120.   120
<result>E</result>
A boy has Rs. 640 in the denominations of one-rupee notes, five-rupee notes and ten-rupee notes. The number of notes of each denomination is equal. What is the total number of notes that he has ?