Permutations and Combinations

Question

Determine the number of terms in an A.P. 3, 8, 13, .......253. Also, find 12th term from the end.

Solution

The given A.P. is : 3, 8, 13, ....., 253
Here, a = 3, d = 8 - 3 = 5
Let there be n terms of an A.P.

∴ $straight t subscript straight n space equals space 253$ or $l italic space italic equals italic space italic 253$
or a + (n - 1)d = 253 or 3 + (n - 1) 5 = 253
or 3 + 5n - 5 = 253 or 5n - 2 = 253
or 5n = 255 or n = 51
Since nth term from end = $<pre>uncaught exception: mkdir(): Permission denied (errno: 2) in /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php at line #56mkdir(): Permission denied in file: /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php line 56 #0 [internal function]: _hx_error_handler(2, 'mkdir(): Permis...', '/home/config_ad...', 56, Array) #1 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php(56): mkdir('/home/config_ad...', 493) #2 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/FolderTreeStorageAndCache.class.php(110): com_wiris_util_sys_Store->mkdirs() #3 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/RenderImpl.class.php(231): com_wiris_plugin_impl_FolderTreeStorageAndCache->codeDigest('mml=<math xmlns...') #4 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/TextServiceImpl.class.php(59): com_wiris_plugin_impl_RenderImpl->computeDigest(NULL, Array) #5 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/service.php(19): com_wiris_plugin_impl_TextServiceImpl->service('mathml2accessib...', Array) #6 {main}</pre>$

∴ 12th term from end = 253 - (12 - 1)5 = 253 - (11) (5) = 253 - 55 = 198

For Daily Free Study Material Join wiredfaculty

Permutations And Combinations

Determine the number of terms in an A.P. 3, 8, 13, .......253. Also, find 12th term from the end.

Some More Questions From Permutations and Combinations Chapter

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Phone Number

Email Address

Loaction