Home » Find r, if 6r78 = 5119

Find r, if 6r78 = 5119

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

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