Answer:
1000
Explanation:
8 = 2³
dcba
In a number written in base 2, the digit a is the units digit, 2^0.
The digit b is the 2's digit, 2^1.
The digit c is the 4's digit, 2².
The digit d is the 8's digit, 2³.
Since 8 = 2³, we need 0 in the units, 2's and 4's digits, and a 1 in the 8's digit.
2 (base 10) = 1000 (base 2)