If you have a part and a whole you can subtract the part from the whole to find the other part. I'm not sure about it, but that's my best guess ;3 Good luck!
Answer: Approximately 146 minutes (or if you need the simplified version the answer is 2 hours and 26 minutes). Step-by-step explanation:
Step 1. Two classes of 21 students. To calculate that you would multiply 21 by 2.
21*2=42
Step 2. So now we know you need 42 individual pictures. If they each take 3 minutes to take you need to multiply 42 by 3.
42*3=126. So now you know it’ll take 126 minutes to take all the individual pictures.
Step 3. Now, there are 2 classes of people and it takes 10 minutes to take each class picture. So do calculate that you need to multiply 10 by 2.
10*2=20. So it’ll take 20 minutes to take both class pictures.
Step 4. Now we know it’ll take 126 minutes to take all the individual photos and 20 minutes to take the class photos. Now to calculate the total amount of time it’ll take to take all the photos you need to add 20 to 126. 126+20=146. So, it’ll take 146 minutes to take all the photos.
Step 5. (You can skip this step if no simplification is needed in your problem) So, we all know there is 60 minutes in an hour so we’ll divide 146 by 60.
146/60=2.43. So, now we know it’ll take 2.43 hours to take all the photos. 2.43 hours is 2 hours and 26 minutes. I hope this helps!
