An inter-species meeting on Mars
100 aliens attended an inter-species meeting on Mars. 76 of them needed breathing apparatus, 52 needed shaded goggles, but 23 aliens didn’t need either. How many aliens needed breathing apparatus goggles?
Word Problem
A bridge is built across a river. One quarter of the bridge is over the left bank of the river and one third of the bridge is over the right bank. The river is 120 m wide. How long is the bridge?
76 + 52 is 128 and that is already more than how much we need. 100 - 23 would be the amount we need and that is 77. Now, we can do 128 - 77 to get 51. 51 is the number we need to subtract. Try and see if you can solve it from here. If not, contact me on the menu page.
ReplyDeleteI thought 51 was the answer
DeleteWe need to subtract 51 from each of the values to get the total adding up to 100.
Delete76 - 51 + 52 - 51 + 23 = 100
We dont subtract 51 from 23 because 51 is the number of aliens who needed both so it is just used for 76 and 52
Now, we can use this to get an answer for the number of aliens needing just breathing apparatus goggles. If 76 needed it and 51 had both, then 76-51=25 is our answer