Word puzzle!

Karen's friends want to buy her a wedding gift. Originally ten friends were going to chip in equally, but then two or them dropped out. Each of the remaining eight friends had to chip in another dollar to bring the total back up to the original amount. How much money did they plan to collect?

40 dollars

Step-by-step explanation:

We can say

x=amount each friend has to pay

Then, the price of the gift would be 10x because there are 10 friends and each pays x dollars. But since two friends dropped out, it will now become 8x. Also, each of the 8 friends has to pay an extra dollar to go back to the original amount, so 8x+8 is also the price of the gift. We set these two expressions equal to each other (because they both represent the price of the gift) so

10x=8x+8. Using the subtraction property of equality (which says if a=b, then a-c=b-c) we subtract 8x from both sides to get

2x=8. Using the division property of equality (which says if a=b, then a/c=b/c) we divide by 2 on both sides to get x=4. But the question asked how much money they planned to collect, or what was the price of the gift, which is 10x, 10*4=40, 40 dollars.