Reasoning
Take the numbers in pairs, square the first, and reverse the digits.
1 1 (1 x 1 = 1, reversed is 1)
2 4 (2 x 2 = 4, reversed is 4)
3 9 (3 x 3 = 9, reversed is 9)
4 61 (4 x 4 = 16, reversed is 61)
5 52 (5 x 5 = 25, reversed is 52)
6 63 (6 x 6 = 36, reversed is 63)
7 94 (7 x 7 = 49, reversed is 94)
so we require:
8 46 (8 x 8 = 64, reversed is 46)
Hint
Light travels over 186,000 miles each second.
Answer
Miles travelled by light in a second.
Reasoning
Light travels over 186,000 miles per second.
There are 2.54cm in an inch, 12 inches in a foot, 3 feet in a yard, and 1760 yards in a mile. So there are 2.54 x 12 x 3 x 1760 = 160,934.4cm in a mile.
Reasoning
These are geometric shapes, the number of sides increases, and the words are reversed.
3 elgnairt = triangle
4 erauqs = square
5 nogatnep = pentagon
6 nogaxeh = hexagon
7 nogatpeh = heptagon
8 nogatco = octagon