Math Is Fun Forum

i would do it this way

you pick out the first tree - there are 9 posibilities and plant it on north or south - 2

so the first tree 9x2 ways
second 8x2
third; 7x2
fourth 6x2
fifth 5x2
sixth 4x2
seventh 3x2
eight 2x2
ninth 1x2

9x2x8x2x7x2x6x2x5x2x4x2x3x2x2x2x2 so 9!x2^10

it's imposible. only numbers with 9 in the front will give you more!

132621

only from 1962 we can form 24 different 4 digit numbers, 24 3-digit numbers, 12 2-digit numbers and 4 1-gigit numbers, 30 gives you only three numbers (30 3 and 0) so there are 65 different numbers!!

I would divide your irregular shape into basic shapes, such as rectangles, trapazium, triangles, semicircles etc.

Forgot to add that you find their areas and add them together :-(

you choose black ink for the card: 1/7;
you choose blue paper for the card: 1/6;
blue ink for the envelope: 1/7;
blue paper for the envelope: 1/7;

we have to multiply probabilities (black ink and blue paper and blue ink and blue paper) - we substitute and with multiplication:

so the answer is: 1/1764

1. P = (e^(-7)* 7^2)/2! = 0.02234121335

where 7 is expeted number of occurences and two the number of occurences we want to get.

2. P(0) + P(1) + P(2)

But I'm really not sure. Hope some guys here will be able to help you with this problem.

so:

the full mark is 100 points

grade 65 is worth 10% of the full mark which is 10 points. you scored 65/100 which is 6.5/100 of the full mark
grade 59 is worth 40% - 23.6/100 of the full mark

so all together you have 30.1/100 before your final.

you want to have more than 60 after your final so you have to score 29.9 on your final. 29.9/50 (the max on the final) is grade 59.8 on your final or more.

10%+40%+60%=110%!!