Five half-full classes + three 3/4 full classes + 2 1/8 empty (which is 7/8 full) classes altogether give us 10 classes without 70 students. Let's assume that one class is x, so we can write it as:
5 * 1/2x + 3 * 3/4x + 2 * 7/8x = 10x - 70
After multiplying and changing it to decimals:
2,5x + 2,25x + 1,75x = 10x - 70
6,5x = 10x - 70 / - 6,5x (both sides)
0 = 3,5x - 70 / + 70 (both sides)
70 = 3,5x / :3,5 (both sides)
x = 20
Check:
5 * 1/2 * 20 + 3 * 3/4 * 20 + 2 * 7/8 * 20 = 10 * 20 - 70
5 * 10 + 3 * 15 + 2 * 17,5 = 200 - 70
50 + 45 + 35 = 130
130 = 130
Correct - there are 20 students in each class (200 students overall)
Answer: There are 200 students in the school when no students are absent.
Gina can ship all 3 books. The books only weigh 4 and 13/16
Answer:
t=2
j=1
Step-by-step explanation:
3 tacos and a juice is $7
3t+j=7
4 tacos and 2 juices is $10
4t+2j=10
We have a simultaneous equation. It can be solved either by substitution method or Elimination method. For the purpose of this question, the elimination method will be used
3t+j=7 Equation 1
4t+2j=10 Equation 2
To eliminate j, we multiply Equation 1 by 2, the coefficient of j in equation 2, so that in both equations, j can have the same coefficient.
2(3t+j=7)
6t+2j=14 Equation 3
We now have
4t+2j=10 Equation 2
6t+2j=14 Equation 3
We subtract equation 2 from equation 3, to eliminate j
6t-4t=2t
2j-2j=0
14-10=4
We have 2t=4
Divide both sides by 2
2t/2=4/2
t=4/2
t=2
Substitute t for 2 in equation 1, to get j
3t+j=7
3(2)+j=7
6+j=7
j=7-6
j=1
One taco cost $2 while 1 juice cost $2
