new houses being built in a neighborhood. Last month,
of them were sold. This month,
of the remaining houses were sold. How many houses are left to be sold?
Of the 45 houses 2/3 were sold which means that 1/3 were unsold. Therefore we have:
45 x 1/3 =15 houses remained unsold last month.
Of the 15 remaining houses 2/5 were sold which means that 3/5 were unsold. Therefore we have:
15 x 3/5 =45/5 =9 houses left to be sold.