How many numbers between 11 and 90 are divisible by 7? Answers:
A) 7
B) 9
C) 11
D) 8
E) 10
The required numbers are 14, 21, 28, 35, .... 77, 84.   This is an A.P. with a = 14 and d = (21 - 14)= 
<gadget id="calculator">(21 - 14)</gadget>
<output>7</output>
7.   Let it contain n terms.   Then, T^n= 84 =&gt; a + (n - 1) d = 84   =&gt; 14 + (n - 1) x 7 = 84 or n = 11.   Answer is 11.
<result>C</result>
How many numbers between 11 and 90 are divisible by 7?