Guest

find the no. of factors ( excluding 1 and the expression itself ) of the product of a^7 b^4 c^3 d e f where a b c d e f r all prime nos..?? plzzz provide the full soln....

find the no. of factors ( excluding 1 and the expression itself ) of the product of a^7 b^4 c^3 d e f   where a b c d e f r all prime nos..??

plzzz provide the full soln....

Grade:12

1 Answers

AJIT AskiitiansExpert-IITD
68 Points
13 years ago

Dear Akhil ,

consider the expression
(1 + a + a2 + a3 + a4 + a5  + a6 + a7) (1 + b + b2 + b3 + b4) (1 + c + c2 + c3) (1 + d) (1 + e) (1 + f)

If you observe the expression , you will find that each term in the expansion is a factor of N = a7b4c3def .  Also the expansion starts from 1 and ends at the number itself  , in between all the factors of numbers are located . so if we can find out the number of terms in the expansion -2 (for 1 and number itself) , we will get the answer, which can be easily seen as  8 X 5 X 4 X 2 X 2 X 2 = 1280 -2 = 1278

Please feel free to post as many doubts on our discussion forum as you can. We are all IITians and here to help you in your IIT JEE preparation.


Now you can win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.

Think You Can Provide A Better Answer ?

ASK QUESTION

Get your questions answered by the expert for free