Final answer:
Danny gave away 60% of his 75 marbles to his friend, which is calculated to be 45 marbles through multiplication and division of percentages.
Step-by-step explanation:
To calculate how many marbles Danny gave to his friend, we need to find 60% of 75 marbles. The calculation for percentage is obtained by multiplying the total number of items by the percentage, then dividing by 100 to get the answer.
Step-by-step calculation:
Write down the total number of marbles: 75.
Write down the percentage Danny gave away: 60%.
Multiply the number of marbles by the percentage: 75 * 60 = 4500.
Divide by 100 to find the final answer: 4500 / 100 = 45 marbles.
Therefore, Danny gave 45 marbles to his friend.