The chemical formula for water is H2<span>O which means that every </span>molecule<span> of water has 2 </span>atoms<span> of hydrogen (H) and one </span>atom<span> of oxygen (O). Here comes the key part. From the Periodic Table of Elements, one sees that one mole of hydrogen </span>atoms weighs <span>1 gram while one mole of oxygen </span>atoms<span> weighs 16 grams.</span>
Answer:
you want 4 correct and 16 incorrect
there are 20 questions
each question has four answers, so
P(right answer) = 1/4
P(wrong answer) = 3/4
----
Since you want 4 correct of 20 we have a combination of 20C4
This is a binomial problem where p = 1/4, q = 3/4 and we get
(20 "choose" 4)*(probability correct)^(number correct)*(probability incorrect)^(number incorrect)
putting numbers in we get
(20c4)*(1/4)^4*(3/4)^16
This gives us
~ .189685
Step-by-step explanation:
Answer:
answer is B
Step-by-step explanation:
Answer:
x<16
Step-by-step explanation:
number<em> n
</em>
eight less than four times a number ... 4 x <em>n</em> - 8
is less than 56 ... < 56
4 x <em>n</em> - 8 < 56
4 x <em>n</em> < 56 + 8
4 x<em> n</em> < 64/4
<em>
n</em> < 64 / 4
<em>n</em> < 16
