Write a question that matches this equation. 45 – n = 15

There were 45 birds on the field , when some of them flew away, only 15 left.
How many birds flew away?

 Hey there :) 

45 - n = 15

Here are few examples:
· The difference between 45 and a number gives 15. What is the number?
· A number less than 45 gives 15. What is the number?
· 45 decreased by a number gives the difference 15. What is the number?
· 15 papers were left unused out of 45 papers. How many papers were used?
· Ray had $45 and he bought some grocery. He was given a change of $15. How much money did he use?

W-14=t. that i think is the answer idk