Answer : The weight of cinnamon and sugar need to use is, 20 g and 80 g respectively.
Step-by-step explanation :
Total weight of mixture = 100 g
Let the weight of cinnamon be, x
And, the weight of sugar will be, (100-x)
Cinnamon costs = 9¢/g
Sugar costs = 6.5¢/g
Mixture costs = 7¢/g
Total cost of cinnamon = 9¢/g × (x)g = (9x)¢
Total cost of sugar = 6.5¢/g × (100-x)g = (650-6.5x)¢
Total cost of mixture = 7¢/g × (100)g = (700)¢
According to question,
(9x)¢ + (650-6.5x)¢ = (700)¢
(9x)¢ - (6.5x)¢ = (700)¢ - (650)¢
(2.5x)¢ = 50¢
x = 20
The weight of cinnamon = x = 20 g
The weight of sugar = 100 - x = 100 - 20 = 80 g