Problema Solution

In the manufacture of a certain type of automobile, four

kinds of major defects and seven kinds of minor defects can

occur. For those situations in which defects do occur, in how

many ways can there be twice as many minor defects as there

are major ones?

Answer provided by our tutors

In order to have twice as many minor defects as there are major ones, we can have:

Case I: 1 major 2 minor

number of ways: (4)(7)(6)


Case II: 2 major 4 minor

number of ways: (4)(3)(7)(6)(5)(4)


Case III: 3 major 6 minor

number of ways: (4)(3)(2)(7)(6)(5)(4)(3)(2)


Total number of ways from all three cases:

(4)(7)(6) + (4)(3)(7)(6)(5)(4) +(4)(3)(2)(7)(6)(5)(4)(3)(2)=131208