How many three digits number greater than 600 can be formed using the digits 4,5,6,7,8?
Answers:
A) 85
B) 65
C) 75
D) 25
E) 15
Clearly repetition of digits allowed. Also the hundredths place of the 3-digit number can be filled in by6,7,8 in 3 ways. Each of the ten's, one's place can be filled in 5 ways. Hence the total number of required numbers = 3*5*5= 
<gadget id="calculator">3*5*5</gadget>
<output>75</output>
75 Answer : 75
<result>C</result>
How many three digits number greater than 600 can be formed using the digits 4,5,6,7,8?