Question

1. A dad holds five coins in his hand. He tells his son that if he can guess the amount of money he is holding within 5% error, he can have the money. The son guesses that dad is holding 81 cents. The dad opens his hand and displays 90 cents. Did the son guess close enough to get the money?

Answer 1

1. A dad holds five coins in his hand. He tells his son that if he can guess the amount of money he is holding within 5% error, he can have the money. The son guesses that dad is holding 81 cents. The dad opens his hand and displays 90 cents. Did the son guess close enough to get the money?

yes

Answer 2

The dad had 90 cents.

Multiply the 90 cents by 5%:

90 x 0.05 = 4.5 cents.

Subtract that from 90:

90 - 4.5 = 85.5 cents.

The lowest guess the son could say was 86 cents to be within 5%

Since the son guessed lower than that he did not get the money.