7........[12]
no of planes that are equidistant from four non-coplanar points is :
a) 3 b) 4 c) 7 d) 9.
visualised the situation and answered...
but someone give me a 'nice' method ... in the sence a 'way' to actually 'solve' ...
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7 Answers
NIshant Sir, has already solvd this on the forum i guess..........
Ans must be 4.
I'll get u the link soon
Three of the 4 points will lie on a plane. So the plane equidistant from the plane (3 points) and the 4th point is the one passing midway between the plane & point and parallel to the plane. Ways to choose such points are 4C3 (=4)
So why is 4 the wrong answer?
anirudh sky just told me..
I missed a case.. when we could have 2 points on one side and 2 mor eon the other
so then it wud be 4C2/2+4C3=7