Answer:
1a. 58/99
1b. 53/90
1c. 29/50
Explanation:
let's start with the easiest one
1.(c)
0.58 = 58/100 = 29/50
that is the simplest possible form, as 29 is a prime number and not a factor of 50.
1.(a)
0.585858585858... = 58×0.0101010101010101...
now, we know that 1/"double digit" (like 1/22) mostly produces a repeating pattern with a period length of 2 after the decimal point.
and we find
1/99 = 0.01010101010101...
so, our solution is
58 × 1/99 = 58/99
that is the simplest possible form, as 58 and 99 do not share any factors.
1.(b)
0.5888888888888... = 0.5 + 0.0888888888888... =
= 0.5 + 8×0.01111111111111... = 0.5 + 8×1/10 × 0.1111111111...
we know how to create 0.11111111111... :
1/9 = 0.111111111111111...
so, our solution is
0.5 + 8 × 1/10 × 1/9 = 0.5 + 8/90 = 5/10 + 8/90 =
= 45/90 + 8/90 = 53/90
this is the simplest possible form, as 53 is already a prime number and not a factor of 90.