Answer:
33%
Step-by-step explanation:
h steps:
Step 1: We make the assumption that 51 is 100% since it is our output value.
Step 2: We next represent the value we seek with $x$.
Step 3: From step 1, it follows that $100\%=51$.
Step 4: In the same vein, $x\%=17$.
Step 5: This gives us a pair of simple equations:
$100\%=51(1)$.
$x\%=17(2)$.
Step 6: By simply dividing equation 1 by equation 2 and taking note of the fact that both the LHS
(left hand side) of both equations have the same unit (%); we have
$\frac{100\%}{x\%}=\frac{51}{17}$
Step 7: Taking the inverse (or reciprocal) of both sides yields
$\frac{x\%}{100\%}=\frac{17}{51}$
$\Rightarrow x=33.33\%$
Therefore, $17$ is $33.33\%$ of $51$.
If there are 12 items adding up to 60%, we want to know how many items more it will take to equal 100% So set up this equation 12/x = .6 then solve for x. x=12/.6 x = 20 now that we know the total you can subtract 12 from 20 and get 8, that is the number of items left on the list.
About 102.5625... I think
Hey there!
The answer is 
We will start by forming an equation to solve this.
So we are starting with a number,
, then doubling it and adding
, which gives us 25.
So:

Now we solve this equation:



Have a super awesome day!