A box of sticks of equal lengths is provided. The minimum number sticks needed
to build a frame to enclose a 3 dimensional volume is??
In a bag containing only blue, red and green marbles, all but 15 are blue, all but
13 are red and all but 12 are green. How many are red?
1. 13
2. 7
3. 25
4. 20
Pls help me with these physics problems?? elaborate and explain...Thankyou!!?
2013-09-02 3:10 pm
回答 (5)
2013-09-02 3:19 pm
✔ 最佳答案
6. a tetrahedron.
2013-09-02 3:20 pm
A triangular pyramid requires 6 sticks.
15 = R + G
13 = B + G
12 = B + R
G - R = 1
So there are 8G and 7R and 5B
Answer 2
15 = R + G
13 = B + G
12 = B + R
G - R = 1
So there are 8G and 7R and 5B
Answer 2
2016-09-18 4:11 am
I am not sure what to say
2016-08-25 1:43 pm
Several identical cubes are arranged in a close-packed single layer. If the area of
the layer is A and the volume of the layer is V, then the number of cubes in the
collection is
the layer is A and the volume of the layer is V, then the number of cubes in the
collection is
2013-09-02 3:31 pm
A. 6 sticks will build a tetrahedron (6 triangular faces).
B. Let there be x reds, y greens, z blues. We have
x + y + z -15 = z, or x + y = 15
Similarly y + z = 13 and x + z = 12. Adding we get:
2x + 2y + 2z = 40 and x + y + z = 20. So x = 20 - (y + z)
=20 - 13 = 7. So 7 are red.
B. Let there be x reds, y greens, z blues. We have
x + y + z -15 = z, or x + y = 15
Similarly y + z = 13 and x + z = 12. Adding we get:
2x + 2y + 2z = 40 and x + y + z = 20. So x = 20 - (y + z)
=20 - 13 = 7. So 7 are red.
收錄日期: 2021-04-20 20:09:00
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130902071042AA9HXc6