Question

The cost of 35 envelopes is Rs 105. How many envelopes can be purchased for Rs 90.

Answer 1

 Hint: Unitary method can be used to find the number of envelopes that can be purchased.

Complete step-by-step answer:
Given, The cost of 35 envelopes is Rs 105.
This means that we can buy 35 envelopes in Rs.105
Using unitary method, In Rs. 105, we can buy 35 envelopes.
Find the number of envelopes that can be purchased in Rs 1,
In Rs 1 , we can buy $\dfrac{35}{105}$ envelope.
Find the number of envelopes that can be purchased in Rs 90,
In Rs. 90 , we can buy $\dfrac{35}{105} \times 90$ envelope.
Simplify the fraction,
In Rs. 90, we can buy 30 envelopes.
Therefore for Rs. 90, 30 envelopes can be purchased .

Note : Find the cost of 1 item then we can find the cost of the given items.