Find r, if 6r78 = 5119
-
A.
3 -
B.
2 -
C.
6 -
D.
5
Correct Answer: Option A
Explanation
6r78 = 5119
6 x 82 + r x 81 + 7 x 8o = 5 x 92 + 1 x 91 + 1 x 9o
6 x 64 + 8r + 7 x 1 = 5 x 81 + 9 + 1 x 1
384 + 8r + 7 = 405 + 9 + 1
391 + 8r = 24
r = (frac{24}{8})
= 3