When I bought three cakes from four cakes A, B, C, D, the total of weight was 1030 gram.
The weight of A is 40g, B is 60g, C is 60g, and D is 90g.
What are two cakes among three cakes I bought ?
The weight of A is 40g, B is 60g, C is 60g, and D is 90g.
What are two cakes among three cakes I bought ?
Answer
A and D
Solution
The weight of B, C, D is a multiple of 30g, but 1030g is not a multiple of 30g.
We can understand that A is included in three cakes.
In addition, the weight of A, B, C is a multiple of 20g, but 1030g is not a multiple of 20g.
We can understand that D is included in three cakes.
