Question

Rice costs $x per kg.

Potatoes cost $(x+1) per kg.
The total cost of 12kg of rice and 7kg of potatoes is $31.70.
What is the cost of 1kg of rice?
Show your working kindly.

Answer 1

x = 1.3

Explanation:

cost of rice for 12kg = 12 * x ($x for each kg)

cost of potatoes for 7kg = 7 * (x+1)

total cost = 12 * x + 7 * (x+1) = 31.7

12x + 7x + 7 = 31.7

19x + 7 = 31.7

subtract 7 from both sides to isolate the variable and its coefficient

19x = 24.7

divide both sides by 19 to find x

x = 1.3