Answer:
D) 18 freshman, 18 sophmores, 30 juniors, 30 seniors
Step-by-step explanation:
ratio given:
320 : 300 : 500 : 510
320 = 300 and 500 = 510
therefore ratio of 300 : 300 : 500 : 500
Ratio of 300 : 500 = 18 : 30
18 : 18 : 30 : 30
P = ( 2 / 3 )s;
s = ( 3 / 5 )t ;
p + s + t = 280 ;
Then, p =( 2 / 3 )( 3 / 5 )t ;
p = ( 2 / 5 )t;
We solve the equation : ( 2 / 5 )t + ( 3 / 5 )t + t = 280 ;
( 2 / 5 )t + ( 3 / 5 )t + ( 5 / 5 )t = ( 1400 / 5 )t;
10t = 1400 ;
t = 1400 ÷ 10 ;
t = 140 postcards has Tim;
p = ( 2 / 5 ) × 140 = 56 postcards has Paul;
s = ( 3 / 5 ) × 140 = 84 postcards has Shawn ;
Answer:
<h2>x = 9, y = -36 → (9, -36)</h2>
Step-by-step explanation:
