An algebra problem by Aditya Dalmia
Algebra
Level
pending
How many different 6 digit numbers can be formed by using 5 and 7 that are divisible by 35?
The answer is 5.
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.
1 solution
The last digit needs to be 5 for divisibility by 5. There are 5 numbers (formed with 5 and 7), with 6 digits which are divisible by both 5 and 7 and hence by 35.
5 5 5 5 5 5 , 5 7 5 5 7 5 , 7 5 5 7 5 5 , 7 5 7 5 7 5 , 7 7 5 7 7 5