Lambda = h/sqrt 2me Therefore lambda1/lambda2 = sqrt E2/E1 .....(1)As it is given that ke becomes nine times Therefore let E1 be initial ke and E2 be final keTherefore E1 = 9E2 Therefore from eqn 1We get....lambda1/lambda2 = sqrt E2/9E2lambda 1/lambda2 = 1/3