State in each case, whether true or false : (i) √2+√3=√5 (ii) 2√4+2=6 (iii) 3√7-2√7=√7 (iv) 2/7 is an irrational number. (v) 5/11 is a rational number. (vi) All rational numbers are real numbers. (vii) All real numbers are rational numbers. (viii) Some real numbers are rational numbers.