When a two-digit number is divided by the sum of its digits, the quotient is 8. On diminishing the ten’s digit by three times the unit’s digit, the remainder obtained is 1. Find the number.

A number of two digits exceeds four times the sum of its digits by 6, and the number is increased by 9 on reversing its digits. Find the number.

If 11 pens and 19 pencils together cost ₹ 502, while 19 pens and 11 pencils together cost ₹ 758, how much do 3 pens and 6 pencils cost together?

5 kg sugar and 7 kg rice together cost ₹ 258, while 7 kg sugar and 5 kg rice together cost ₹ 246. Find the total cost of 8 kg sugar and 10 kg rice.