What percent of 400 is 20?

Answer: 5%

Explanation 1:

20:400*100 =

(20*100) : 400 =

2000:400 = 5

Explanation 2:

Step 1: We make the assumption that 400 is 100% since it is our output value.

Step 2: We next represent the value we seek with $x$x .

Step 3: From step 1, it follows that $100/%=400$100%=400 .

Step 4: In the same vein, $x/%=20$x%=20 .

Step 5: This gives us a pair of simple equations:

$100/%=400 (1) $100%=400 (1) .

$x/%=20 (2) $x%=20 (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

$/frac{100/%}{x/%}=/frac{400}{20}$

100%

x% =

400

20

Step 7: Taking the inverse (or reciprocal) of both sides yields

$/frac{x/%}{100/%}=/frac{20}{400}$

x%

100% =

20

400

$/Rightarrow x=5/%$⇒x=5%

Therefore, $20$20 is $5/%$5% of $400$400 .