Oliver was drawing and replacing balls out of a bag. He first drew 3 balls, replaced 2 of them, drew out 4 more balls and replaced 1. How many balls did he have left in his hand?
After drawing 3 balls, he replaced 2 of them, so he still has 1 ball in his hand.
Then he drew out 4 more balls and replaced 1, so he still has 4 balls in his hand.
Therefore, Oliver has a total of 1 + 4 = 5 balls left in his hand.
Let's break down the steps and calculate the number of balls left in Oliver's hand.
Step 1: Oliver draws 3 balls
Initially, Oliver has 0 balls in his hand.
After drawing the first ball, Oliver has 1 ball in his hand.
After drawing the second ball, Oliver has 2 balls in his hand.
After drawing the third ball, Oliver has 3 balls in his hand.
Step 2: Oliver replaces 2 balls
Oliver replaces 2 of the 3 balls he had in his hand.
After replacing the first ball, Oliver still has 2 balls in his hand.
After replacing the second ball, Oliver still has 2 balls in his hand.
Step 3: Oliver draws 4 more balls
After the replacement, Oliver has 2 balls in his hand.
After drawing the fourth ball, Oliver has 3 balls in his hand.
After drawing the fifth ball, Oliver has 4 balls in his hand.
After drawing the sixth ball, Oliver has 5 balls in his hand.
After drawing the seventh ball, Oliver has 6 balls in his hand.
Step 4: Oliver replaces 1 ball
After drawing 7 balls, Oliver has 6 balls in his hand.
After replacing 1 ball, Oliver still has 6 balls in his hand.
So, after all the steps, Oliver is left with 6 balls in his hand.
To find out how many balls Oliver has left in his hand, let's break down the steps he took.
1. Oliver first drew 3 balls from the bag. This means he initially had 3 balls in his hand.
2. Next, he replaced 2 of the balls. This means he put back 2 balls from the 3 he initially had, leaving him with 1 ball in his hand.
3. Then, Oliver drew out 4 more balls from the bag. Since he had 1 ball left from the previous step, he now has a total of 1 + 4 = 5 balls in his hand.
4. Finally, he replaced 1 more ball. This means he put back 1 ball from the 5 he had, leaving him with 5 - 1 = 4 balls in his hand.
So, Oliver has 4 balls left in his hand after following these steps.