If d=(10^10)-47, what is the sum of all the digit of d? Choose the correct choice from the following answers
A) 40	B) 45	C) 50	D) 55	E) 80
Start small and check for any pattern:   10^2 - 47 = 53 -&gt; number of digits = power of 10; number of 9s = (power of 10) - 2; 53 is the last 2 digits   10^3 - 47 = 953 -&gt; number of digits = power of 10; number of 9s = (power of 10) - 2; 53 is the last 2 digits   ...extrapolate   10^10 - 47 -&gt; number of digits = 10; number of 9s = 8; 53 will be the last 2 digits   d = 9*8 + 5 + 3= 
<gadget id="calculator">9*8 + 5 + 3</gadget>
<output>80</output>
80.   Answer (80).
<result>E</result>
If d=(10^10)-47, what is the sum of all the digit of d?