Question

cost of 105 envelopes is Rupees 35 how many envelopes can be purchased for rupees 10 and what will be cost for 50 envenlopes ?

Answer 1

cost of 105 envelopes is Rs. 35
cost of one envelop is 105/35 = Rs. 3

envelopes that can be purchased for Rs. 10 is 10/3 = approx. 3 envelopes

cost of 50 envelopes is 50*3 = Rs. 150

....hope it helps you.....

Answer 2

Number of envelopes that can be bought in 35 rupees = 105 envelopes
Number of envelopes that can be bought in 10 rupees = ?

Number of envelopes that can be bought in 10 rupees = 10 x 105 /35
                                                                                       = 1050 / 35
                                                                                        = 30

Cost of 50 envelopes = 35 / 105 x 50
                                   = 16.66 rupees