Which of the following statements is correct?

a- Urban waste disposal is a serious problem in India. 

b- In metropolitan cities like Mumbai, Kolkata etc., 90 per cent of the solid waste left uncollected accumulate on streets, in open spaces between houses and in wastelands.

Only statement a is correct.

Urban waste disposal is a serious problem in India. In metropolitan cities like Mumbai, Kolkata, Chennai, Bengaluru, etc., about 90 per cent of the solid waste is collected and disposed of. But in most other cities and towns in the country, about 30 to 50 per cent of the waste generated is left uncollected which accumulates on streets, in open spaces between houses and in wastelands leading to serious health hazards.