To solve for this, set up a proportion.
21/40 = x/100.
Cross multiply the fraction's numerators with the denominators;
21 x 100, 40 and x.
2100/40x.
Divide both numbers by 40 to get x.
2100/40 = 52.5
21 is 52.5% of 40.
I hope this helps!
You do 2x20 which is basically 2x2 (4) add a zero and your answer is 40
You factor out primes from the root, for example:
root 100
you can get 10 from it, or we'll use 5
100/5=20
20/5=4
root 4= 2
because there are 2 "5" we can bring that out of the root, there are 2 "2" so we bring that out too.
When a number is taking out of a root, the 2 exact same numbers become one. in this case, there are ONE 5 and ONE 2 outside the root. then You multiply 5 and 2 together, and you get 10
17>n because 17 is more than n