Cost of 4 dozen bananas is Rs 180. How many bananas can be purchased for Rs 90?

As the cost of 4 dozen bananas is Rs 180 then the cost of 1 banana is around Rs 3.7. Given that, Cost of 4 dozen bananas = 180 rupees ∴Cost of 1 dozen bananas = 1804=45 rupees …(1) As we know that 1 dozen =12items. ∴1 dozen bananas contains 12 bananas. From equation (1), we calculate the cost of 1 dozen i.e. 12 bananas =45rupees ∴the cost of 1 banana =4512rupees …(2) Since, we have to calculate the number of bananas that can be purchased for Rs 90, first we will calculate the number of bananas we can purchase for 1 rupee. From equation (2), we calculate the number of bananas for 1 rupee =1245 Now, Number of bananas for 90 rupees =90×1245 =24 ∴ Total number of 24 bananas can be purchased for 90 rupees. Note: In such types of problems, one should always try to calculate the items per 1 rupee first and then multiply it by the required amount asked in the question or calculate the cost per 1 item and multiply it by the number of items.