In June, Mr Ang was given a sum of $25 000. He spent 20% of the sum on
electrical bill, 70% on cleaning services and the rest on Internet data plan. In
July, the sum given was reduced. He spent the same amount of money on
electrical bill and reduced his spending on cleaning services by $2700. He
spent the remaining 10% of the sum given in July on Internet data plan. By what
percentage was the sum of money given to Mr Ang reduced?