This problem involves a few steps. First, you need to determine how many eighth graders you have given that 112 represent 70% of the total number of eighth graders. You can solve this using a proportion:
Cross-multiply and divide: 70x = 11200 or 70x/70 = 11200/70 or x = 160
Since there are 160 total eighth graders and this is of the amount of seventh graders, we can set up an equation to solve for the total amount of seventh graders:
160 = x
Multiply by the reciprocal of your fraction on both sides:
Step-by-step explanation: If she runs 7 miles for 50 minutes, if you half it, she runs 3.5 miles in 25 minutes. This means if you add 7 and 3.5 miles, you would add 50 and 25 minutes,
So if 32 oz is 20% more than the average bottle, you multiply 32 by .20 which gives you 6.4. This means that the 32 oz bottle is 6.4 oz more than the regular bottle. Furthermore, 32 - 6.4 = 25.6 so that's how big the typical bottle is.
