Explanation
From Maryam's purchase:
4C + T = 1800
From Fatima's purchase:
6C + 2T = 3000
We can solve these equations using substitution or elimination. Let's use elimination.
Multiplying the first equation by 2:
8C + 2T = 3600
Now subtracting the second equation from this:
(8C + 2T) - (6C + 2T) = 3600 - 3000
2C = 600
C = 300