Question

(a) 2.5% of what is 2.21?
(b) What number is 186% of 30.5?

Answer 1

Step-by-step explanation:

2.21:2.5*100 =

(2.21*100):2.5 =

221:2.5 = 88.4

Now we have: 2.21 is what percent of 2.5 = 88.4

Question: 2.21 is what percent of 2.5?

Percentage solution with steps:

Step 1: We make the assumption that 2.5 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 $100\%=2.5$.

Step 4: In the same vein, $x\%=2.21$.

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

$100\%=2.5(1)$.

$x\%=2.21(2)$.

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

$\frac{100\%}{x\%}=\frac{2.5}{2.21}$

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

$\frac{x\%}{100\%}=\frac{2.21}{2.5}$

$\Rightarrow x=88.4\%$

Answer 2

Answer:

a) 2.5% of x = 2.21

2.5/100x = 2.21

2.5x = 221

x = 221/2.5

simplify it further.

b) x = 186% of 30.5

x = 186/100 * 30.5

x = 5673/100

x =56.73