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If a, b, c are in Arithmetic Progression, what will be the sequence of ab, ac, bc?

(1) Arithmetic Progression
(2) Geometric Progression
(3) Harmonic Progression
(4) Arithmetico - Geometric sequence
(5) none of the above

Let us take for example, the numbers in AP to be 1,2 and 3

ab = 2
ac = 3
bc = 6

The sequence = 2,3,6 ==> Is a combination of Arithmetic and Geo series.

Let s see this: 2 + 2 * ( 1/2) = 3
3 + 3 * (2 / 2) = 6 and So on..... A bit tricky one. but was able to deduce with sub of two values, 1,2,3 and 2,4,6. it works for both the seq. Try if you want.

Post me if you have any other shorter methods.....

A small concept
If a,b,c are in AP
1/a ,1/b, 1/c are in HP


Given Numbers are ab,ac and bc
Divide all the three by abc we get 1/c,1/b, 1/a
which will be in HP
So answer is HP.