1. need solutions

Two rectangles are similar. If their dimensions are 4 by 5 and y and 5, find the value fo y > 5

4 coins are labled as 2, 3, 4 and 5. When 2 coins are drawn without looking, what is the probability that their sum is greater than 8?

2. Originally Posted by sri340
Two rectangles are similar. If their dimensions are 4 by 5 and y and 5, find the value fo y > 5
Let:
$\displaystyle L_{1} = 4$

$\displaystyle W_{1} = 5$

The ratio between $\displaystyle L_{1}$ and $\displaystyle W_{1}$ is $\displaystyle \frac{5}{4}$

Then:
$\displaystyle L_{2} = 5$

$\displaystyle W_{2} = \frac{5}{4} \times 5 = \frac{25}{4} = 6,25$

Originally Posted by sri340
4 coins are labled as 2, 3, 4 and 5. When 2 coins are drawn without looking, what is the probability that their sum is greater than 8?
So we have to draw coins 4 and 5.

The probability of drawing 4 is $\displaystyle \frac{1}{4}$

The probability of drawing 5 is $\displaystyle \frac{1}{3}$

Multiply the events.

Probability that sum is greater than 8: $\displaystyle \frac{1}{12}$

(By the way, if you draw the 5 first, its probability will be $\displaystyle \frac{1}{4}$, and of course the probability of drawing a 4 would then be $\displaystyle \frac{1}{3}$.

3. originally posted by sri340 part b four coins

four coins 2,3,4,5 are drawn from a box.probability of getting anumber greater than 8.
there are six outcomes 23,24, 25, 34, 35,45 and only one is favorable.
probability is thus 0ne in six.

bj