Question 1046566
.
How many natural numbers upto 990 are divisible by 5 and 9 both but not by 7 ?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


<pre>
{{{990/(5*9)}}} = 22 natural numbers are divisible by 5 and 9 both.


Of them, 3 are divisible by 7: 45*7 = 315,  2*(45*7) = 630,  and 3*(45*7) = 945.


22 - 3 = 19.


<U>Answer</U>.  19 natural numbers.
</pre>