Question

One term in the series is wrong. Find the wrong term.

Please tell the answer with a step by step explanation. If you do so, I will mark as brainliest.

Answer 1

Series :- 1,3, 10, 21 , 64, 129, 356, 777 .

We have to find the wrong number in the series . and Tell the logic also. and right Number also.

Lets see the pattern Now :-

→ 1 * 2 + 1 = 3

→ 3 * 3 + 1 = 10

→ 10 * 2 + 1 = 21

→ 21 * 3 + 1 = 64

As we can see our Pattern is Multiply by 2 & 3 alternatively and adding 1 .

So, Next will be ,

→ 64 * 2 + 1 = 129

And, Now,

→ 129 * 3 + 1 = 387 + 1 = 388 .

Therefore , 356 is wrong in The series.

Now, lets Check next also,

→ 388 * 2 + 1 = 776 + 1 = 777.

Hence, our 388 is correct Term in the series...

Answer 2

${ \red{ \huge{ \underline{ \bold{Question:-}}}}}$



➠ 1, 3, 10, 21, 64, 129, 356, 777



One term in the series is wrong. Find the wrong term ❔



${ \red{ \bold{ \huge{ \underline{Solution:-}}}}}$



${ \bold{ \pink{GIVEN \: SERIES- }}}$



➠ 1, 3, 10, 21, 64, 129, 356, 777......



${ \bold{ \underline{ \blue{the \: series \: pattern \: is}}}}$



➺ ( × 2 + 1) , ( × 3 + 1 ), (×2 + 1 ), (×3 + 1 ),.........



i.e., multiplication of 2 and 3 alternatively and addition of 1


Series pattern given series
━━━━━━━ ━━━━━━━



1 .......................................1 ✔



( 1×2)+1 =3...................... 3 ✔



(3×3)+1 = 10.................. 10 ✔




(10×2)+1 = 21................ 21 ✔




(21×3) +1 = 64 .............64 ✔




(64×2)+1 = 129.......... 129 ✔




(129×3)+1 = 388 .......356 ❌




(388×2)+1 = 777........ 777 ✔



thus, 356 is the wrong term in the given series



and it should be 388.....



${ \bold{ \pink{CORRECT \: SERIES- }}}$



➠ 1, 3, 10, 21, 64, 129, 388, 777....