Question

If alvin sold 60% of his baseball cards, gave away 30% of those that were left, and still had 40 baseball cards in his possession, how many baseball cards did alvin have to begin with?

Answer 1

Answer:

The number of baseball card to begin with is 143

Step-by-step explanation:

Let The number of baseball cards = x

The number of sold baseball card = 60% of x

                                                         = 0.6 x

The number of left baseball card = x - 0.6 x = 0.4 x

The number of card gave away = 30 % of left cards

                                                     = 0.3 × 0.4 x = 0.12 x

The number of card left in his possession = 40

So, 0.6 x + 0.12 x + 40 = x

Or,  40 = x - 0.6 x - 0.12 x

Or,  40 = 0.28 x

∴   x = $\frac{40}{0.28}$  =  142.85 ≈ 143

Hence The number of baseball card to begin with is 143  Answer