2014-10-29

192. Crossed lines

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In the diagram are 4 lines, none parallel, resulting in 6 points of intersection.  If 7 additional lines are drawn, to make a total of 11 lines, none parallel, determine the number of points of intersection.  (Assume only two lines intersect at any one point.)

2014-10-28

191. Iron truss bridge


Train on bridge at Worcester, England - DSCF0803
A train of length 160 m is traveling at a speed of 20 ㎧ (metres per second).  The train begins to cross an iron truss bridge of length 120 m.  Determine how many seconds it takes the train to cross the bridge.

2014-10-27

190. Sliced pepperoni

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pepperoni
The top of a cylinder with radius 3 cm is sliced at an angle, as shown in the diagram.  Determine the volume of the resultant solid.