Answer:
x = 22
Step-by-step explanation:
x = 7 + 15
x = 22
Semester 1:
let the number of students in the art class be 2a, and the number of the students in the gym class be 7a. (check: the ratio is 2a:7a = 2:7)
so the total number of students is 9a.
semester 2:
the 9a students are go to the art class and gym class at a a ratio of 5: 4,
so 5a students go to the art class, and 4a students go to the gym class.
<span>75 students are in art class in second semester means that 5a=75,
so a=75/5=15.
In the 1st semester the number of students was:
art class: 2a=2*15=30
gym class: 7a=7*15=105</span>
3 gallons of acid = 100% concentration acid
? (water+acid) gallons = 15 concentration acid
Note: Every gallon of water added reduces the percentage concentration of acid. Therefore, the relationship is inverse proportionality.
Solution:
Total number of gallons (water+acid) = (3*100)/15 = 20 gallons
Therefore, gallons of water = 20-3 = 17 gallons
