Question

The list is $6,10,18,34,66$.
The first number in the list above is $6$. Which of the following gives a rule for finding each successive number in the list?

• A. Add $4$ to the preceding number.
• B. Take $\frac{1}{2}$ of the preceding number and then add $7$ to that result.
• C. Double the preceding number and then subtract $2$ from that result.
• D. Subtract $2$ from the preceding number and then double that result.
• E. Triple the preceding number and then subtract $8$ from that result.

Answer 1

The correct option is C Double the preceding number and then subtract $2$ from that result.

Given, $6,10,18,34,64$

(A) Add $4$ to preceding number

Then $6+4=10,10+4=14,18+4=22$ is not true

(B) Take half of the preceding number and add $7$ to that result

Then $\frac{6}{2}+7=10,\frac{10}{2}+7=12,\frac{18}{2}+7=\mathrm{16.......}$ is not true

(C) Double the preceding number and subtract $2$

$6\times 2-2=10,10\times 2-2=18,18\times 2-2=\mathrm{34.................}$

That is true

Hence, (C) is the write answer