Answer:
My best answer is that the probability is 35/100 that the student chosen at random owns neither a laptop nor a mobile phone.
Step-by-step explanation:
If you go back and read the introductory passage, you will notice it says, "In a group of 100 students... 35 own either a laptop or a mobile phone, but not both." And I think the other numbers, I.E. 25 and 40, were just meant to throw us off. Therefore, I think 35/100 is the probability.
Answer:
t(d) = d/65
Step-by-step explanation:
To solve for t, divide by its coefficient:
d = 65t
d/65 = 65t/65 . . divide* by 65
d/65 = t . . . . . . . simplify
Then you can write it in function form if you like:
t(d) = d/65
_____
* Of course, the rules of equality say you must divide <em>both sides</em> of the equation by the same number.
Answer:
a) 1+2+3+4+...+396+397+398+399=79800
b) 1+2+3+4+...+546+547+548+549=150975
c) 2+4+6+8+...+72+74+76+78=1560
Step-by-step explanation:
We know that a summation formula for the first n natural numbers:
1+2+3+...+(n-2)+(n-1)+n=\frac{n(n+1)}{2}
We use the formula, we get
a) 1+2+3+4+...+396+397+398+399=\frac{399·(399+1)}{2}=\frac{399· 400}{2}=399· 200=79800
b) 1+2+3+4+...+546+547+548+549=\frac{549·(549+1)}{2}=\frac{549· 550}{2}=549· 275=150975
c)2+4+6+8+...+72+74+76+78=S / ( :2)
1+2+3+4+...+36+37+38+39=S/2
\frac{39·(39+1)}{2}=S/2
\frac{39·40}{2}=S/2
39·40=S
1560=S
Therefore, we get
2+4+6+8+...+72+74+76+78=1560
35 lbs, your welcome even though you probably don't need the answer anymore
