Question

A number series 5 , 7 , 20 , 21 , 80 , 63 , ? , 189 is given which is in accordance with certain rule.What is the correct answer for the place of interrogation.

Answer 1

5,7,20,21,80,63,320,189

Answer 2

Answer:

In the given series we should find the logic between each terms, then only we can find the missing term in the series.

Final Series: $5 , 7 , 20 , 21 , 80 , 63 , 320 , 189$

Step-by-step explanation:

From the given question, We should find the logic between each terms in the series.

Step 1: First we should find the logic for Odd positioned terms.Odd positioned terms should multiply by 4.That is,

                    $5*4=20$

                  $20*4=80$

Similarly we should do the same again.

                 $80*4=320$ ⇒ Missing term

Step 2: Now we should find the logic for Even positioned terms.Even positioned terms should multiply by 3.That is,

                  $7*3=21$

                $21*3=63$

                $63*3=189$

• Final Series: $5 , 7 , 20 , 21 , 80 , 63 , 320 , 189$