Let the pair fraction F1 and F2
∴ According to the question
F1+F2=711......(i)
F1−F2=211......(ii)
Adding the equation (i) and (ii) we get that
2F1=711+211=7+211=911
⇒F1=911×12=922
Put the value of F1 in equation (i) we get that
⇒911+F2=711
⇒F2=711−922=711×22−922=1422−922=14−922
⇒F2=522