Logical Reasoning - Number Series - Discussion

Discussion Forum : Number Series - Type 4 (Q.No. 2)

Number Series

Directions to Solve

Find the number that fits somewhere into the middle of the series. Some of the items involve both numbers and letters

Look at this series: 664, 332, 340, 170, ____, 89, ... What number should fill the blank?

109

178

Answer: Option

Explanation:

This is an alternating division and addition series: First, divide by 2, and then add 8.

Discussion:

32 comments Page 1 of 4.

Sathesh said: 1 decade ago

How is possible 178?

Bakiya said: 1 decade ago

Yes, how its possible. I think ans is wrong. The correct answer is 85. 170/2=85 then add 4.

Chinna said: 1 decade ago

in the above split it into 3 parts each part contains 2 nos...
in the each part the 1st no is the double of the 2nd no...
that is
664=2*332
340=2*170
178=2*89

Saurabh said: 1 decade ago

first divide by 2 and then add 8 it is clearly written

664/2=332
332+8=340
340/2=170
170+8=178

Satish said: 1 decade ago

Thanks saurabh ji.

Manikandan said: 1 decade ago

Take the 2nd, 4th and 6th numbers. Odd position=even position*2. For this sum it ll work as simple as that.

Reet said: 1 decade ago

I think i can find a easier way..

664-332=332
340-170=170

So in the case of 89. We must have to do (89+89)= 178

So, only thats why it can continue the series like

178-89=89

Hope i can help you..

Rahul said: 1 decade ago

170*2=340
332*2=664
so
89*2=178 ans

Kenneth Tombing said: 1 decade ago

The pattern is reversed in this case. Its easy if calculated from the end.

Neetu said: 1 decade ago

I agree with kenneth we have to look form both the ends from reverse way we can see the previous no. of last the no. will be the double of it.

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