Find the sum of all the four digit numbers which are formed by digits 1, 2, 5, 6
A.
B.
C.
D. Options:
A) 933510	B) 93324	C) 65120	D) 8400	E) 7400
There are 4!=24 four digit numbers which are formed by digits 1, 2, 5, 6.   Obviously  24/4= 
<gadget id="calculator"> 24/4</gadget>
<output>6</output>
6 numbers will end with 1; 6 numbers will end with 2, 6 numbers with 5 and 6 numbers with 6.   6*1+6*2+6*5+6*6=6*14= 
<gadget id="calculator">6*14</gadget>
<output>84</output>
84, which means that the sum of all these 24 numbers must end by 4, only answer choice with 4 at the end is B.   Answer: 93324.
<result>B</result>
Find the sum of all the four digit numbers which are formed by digits 1, 2, 5, 6
A.
B.
C.
D.