There are only red, blue and green counters in a bag. There are 4 red counters.
There are 5 blue counters.
There is 1 green counter.
Matt takes a counter at random from the bag.
a) What is the probability that the counter is red?
Give your answer as a fraction.
b)
What is the probability that the counter is not blue?
Give your answer as a fraction.

A 4/10

B 5/10

Step-by-step explanation:

A because there are 4 out of the 10 that are red

B because there 5 out of the 10 that are not blue

geometry: triangles

solvers

lessons

answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

25.45584