general Maths Puzzle

The number of pairs of positive integers (a,b) where a and b are prime numbers
and a^2-2b^2=1 ,is
a)0 b)1 c)2 d)8

Read Solution (Total 1)

a=3,b=2

so 1 pair of positive integers (a,b) where a and b are prime numbers.
12 years agoHelpfull: Yes(0) No(0)

general Other Question

150 workers were engaged to finish a job in a certain number of days. 4 workers dropped out on second day, 4 more workers dropped out on the third day and so on. It took 8 more days to finish the work. Find the number of days in which the work was completed. When 3/4th of a unit's digit is added to the ten's digit of a two digit number, the sum of the digits becomes 10. If 1/4th of the ten's digit added to the unit digit, then the sum of the digits is 3 less than the sum of the original digits. What is the number ?