A half-life of the isotope is 15 days and at start its mass is 32 g.
A table:
t: m:
0 32 g
15 16 g
30 8 g
45 4 g
60 2 g
75 1 g
In the first column is used an arithmetic sequence ( a 1 = 0, d = 15 ).
In the second column is used a geometric sequence ( a 1 = 32, r = 1/2 )
To solve for x and y, you need to know if the triangles are congruent. They are because of their congruent sides and exterior angles are the same measure.
Now you know that the triangles are congruent, you can set up a proportion for the side lengths you are looking for.
For x...
22/10=x/12. Then cross mutiply. x =26.4
You can do this because the triangles are congruent.
For y...
22/10 =37.4/y. Then you cross multiply. y=17
The correct answer is B.
First of all you have to make them equal to each other. What I mean is the following
3x+20=2x+40
Then you should just solve for x
Okay, so the answer is 5/9. “Someone” was correct. The subtracting of 100 from 225 came from the 100 already being used out of that 225. If you subtract that, you’re left with how much space left. Place those back into the fraction and simplify and you get our answer.
1) If a card is drawn from a pack of 52 cards of which 26 are black (13 spades A, 2, 3,…, 10, J, Q, K); 13 are clovers); and 26 are red (13 hearts and 13 diamonds), find the probability of:
a) that the letter is a K.
b) that the card is red.
c) That the card is diamond.
Help them
