Product of two natural numbers is 7. Then, the sum of reciprocals of their squares is
Choose the correct answer:
A) 50/49  B) 1/289  C) 290/90  D) 290/19  E) None of these
Explanation:   If the numbers are a, b, then ab = 7,   as 17 is a prime number, so a = 1, b = 7.   1/a2+1/b2=1/1(2)+1/7(2)   1/ 2+1/ 2= 
<gadget id="calculator">1/ 2+1/ 2</gadget>
<output>1</output>
1/1(2)+1/7(2)=50/49   Option 50/49
<result>A</result>
Product of two natural numbers is 7. Then, the sum of reciprocals of their squares is