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The next term in the series $81, 54, 36, 24,\dots$ is_________.

I'm getting 15 by taking successive difference & forming its series.

We get next term in sequence by $\left(\dfrac{X}{3}\right)\times 2$
$\dfrac{81}{3} =27\times 2 = 54$

$\dfrac{54}{3} =18\times 2 =36$

$\dfrac{36}{3} =12\times 2 = 24$

$\dfrac{24}{3} = 8\times 2 = 16$

below arrangement is supporting 15 as another possible answer?

am i wrong?

81                    54                 36                 24            15

3*27                3*18             3*12              3*8          3*5

27-18=9           18-12=6       12-8=4       8-5=3

9-6=3              6-4=2           4-3=1

Yes I approached it in the same way.

ALTERNATE LOGIC (Look at the number of 2's)

$81 = 3 \times 3 \times 3 \times 3$

$54 = 3 \times 3 \times 3 \times$$2 36 = 3 \times 3 \times$$ 2 \times 2$

$24= 3 \times$$2 \times 2 \times 2$

$16=$ $2 \times 2 \times 2 \times 2$

I am also getting 15 as the answer.
What is the correct answer??15 or 16
its 24=3*2*2*2

12=2*2*2*2=16
$81,54,36,24,$______

$\dfrac{81}{1.5} = 54$

$\dfrac{54}{1.5} = 36$

$\dfrac{36}{1.5} = 24$

$\dfrac{24}{1.5} = 16$

So, the correct answer is $16.$

1 comment

Sir, you get these series assumption by intuition itself or there’s some trick or concept behind it?
By successive subtraction, I’m getting 15 as answer.
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