Question

买一本书要付给售货员7元8角有多少种付钱方法

买一本书要付给售货员7元8角有多少种付钱方法

Answer 1

In[137]:= Length@
Solve[{x + 2 y + 5 z + 10 i + 50 k == 78, x >= 0, y >= 0, z >= 0,
i >= 0, k >= 0}, {x, y, z, i, k}, Integers]

Out[137]= 1174
{x -> 0, y -> 4, z -> 0, i -> 2, k -> 1}, {x -> 0, y -> 4, z -> 0,
i -> 7, k -> 0}, {x -> 0, y -> 4, z -> 2, i -> 1, k -> 1}, {x -> 0,
y -> 4, z -> 2, i -> 6, k -> 0}, {x -> 0, y -> 4, z -> 4, i -> 0,
k -> 1}, {x -> 0, y -> 4, z -> 4, i -> 5, k -> 0}
....