Answer:

Step-by-step explanation:
Before adding we require the fractions to have a common denominator
The lowest common denominator of 2, 5 and 3 is 30, thus
+
+ 
=
+
+ 
Add the numerators leaving the denominator
=
= 
12^2 +b^2 = 20^2 because of the Pythagorean theorem
144 + b^2 =400
B^2 =256
B=16
................
Step-by-step explanation:
it would at LEAST be like around 20-30 because a 0 can drop something FAST
Answer:
18
Step-by-step explanation:
90% of 20 is 18