Clara collects stamps from foreign countries. In June, she gave 20 pe

Answer = C. 40%

Say initial stamps = 100

Given in June \(= \frac{100*20}{100} = 20\)

Balance = 80

Given in July \(= \frac{80*25}{100} = 20\)

Balance = 60

Total given = 20+20 = 40

OFFICIAL SOLUTION:

(C) First, Clara gave away 20% of her stamps, which means she kept 80%. Then, she gave away 25% of her remaining collection, so she was left with 75% of 80% of her original collection. To determine how many stamps she had left, multiply the two amounts:(80%)(75%) = 60%.

Thus, if Clara kept 60% of her stamps, then she gave away 40% of the original number.

The correct answer is choice (C).

Alternate Solution (Algebraic):

Let X be the original number of stamps in Clara's collection. She gave away 20% or 0.20X, and then gave away 25% of her remaining collection, or 0.25(0.8X).

If we add these two together we get the percent of her collection that she gave away:
0.20X + 0.25(0.8X) = 0.20X + 0.20X= 0.40X

Again we see that Clara gave away 40% of her collection in June and July.

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