Terms of an AP

Algebra Level 2

Find the sum of ( m n ) t h { \left( m-n \right) }^{ th } and ( m + n ) t h { \left( m+n \right) }^{ th } terms if m t h { m }^{ th } is 5 5 .

D e t a i l s : Details:

All terms are terms of an A.P.


The answer is 10.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

2 solutions

If m m th term is 5 5 , m n m-n th term is 5 n d 5 - nd if d d is the difference. m + n m+n th term is also 5 + n d 5 + nd .

Therefore, the sum = 5 n d + 5 + n d = 10 = 5-nd + 5+nd = \boxed{10} . No matter what the difference is, they cancel out. ~~~

This is such a troll question! :D

Krishna Ar - 6 years, 8 months ago

Log in to reply

OVERRATED ._.

math man - 6 years, 8 months ago

Log in to reply

Yes, you are right math man.. I was shocked when I saw that it is for 125 points.

Archit Boobna - 6 years, 8 months ago

Solving is our tasks.

shivamani patil - 6 years, 8 months ago
Sanjeet Raria
Sep 27, 2014

The series is A.P & its m t h mth term is 5.

Let's think of a simplest series having these properties: 5 , 5 , 5 , 5 , . . . . 5, 5, 5, 5, .... . Now we can give values to m & n as we please without breaking any order. Let m = 3 , n = 1 m=3, n=1 Now one can get the answer which is 5 + 5 = 10 5+5=\boxed{10} .

This simple method of arriving at the answer very fast is totally logical \textbf{is totally logical} . Such methods are appropriate only when they are not breaking the guidelines of logic. \textit{Such methods are appropriate only when they are not breaking the guidelines of logic.}

such methods are really useful for functions,, when a particular property of some function is given,, while the actual or most general solutions involve not assuming the function as any known function and directly using the property given in question,, it is often convenient to compare it and find some known function that satisfies the property and thus easily get answer,, especially for objective questions :)

Mvs Saketh - 6 years, 8 months ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...