Tea served in a canteen is made from a mixture of two different types of tea, type A and type B. Type A costs €12.15 per kg. Type B costs €12.90 per kg. The mixture costs €12.65 per kg.
If the mixture contains 7kg of type A, how many kilograms of type B does it contain?
The Attempt at a Solution
all i've written so far is: 12.15 x 7 = €85.05
and i dont even know where im going with that