Question

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

Answer 1

Hint : 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
$\therefore $Cost of 1 dozen bananas = $\dfrac{{180}}{4} = 45$ rupees $ \ldots \left( 1 \right)$
As we know that 1 dozen $ = 12$items.
$\therefore $1 dozen bananas contains $12$ bananas.
From equation $\left( 1 \right)$, we calculate the cost of 1 dozen i.e. 12 bananas $ = 45$rupees
$\therefore $the cost of 1 banana $ = \dfrac{{45}}{{12}}$rupees $ \ldots \left( 2 \right)$

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 $\left( 2 \right)$, we calculate the number of bananas for 1 rupee $ = \dfrac{{12}}{{45}}$
Now, Number of bananas for 90 rupees $ = 90 \times \dfrac{{12}}{{45}}$
$ = 24$
$\therefore $ 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.