Inflation eased marginally to 9.59 per cent in April, but cost of some vegetables and metals remained high.The wholesale price-based inflation cooled from 9.90 per cent in March mainly on account of decline in prices of fruits, onions, wheat and cereals. According to the monthly inflation data, potato prices fell 28.70 per cent in April, and onion prices dropped 11.62 per cent. Iron and Steel prices rose by 11.40 per cent in April compared to March. Sugar prices fell by 5.74 per cent on monthly basis, but turned costlier compared to last year.