Answer:
B) 3:4
Step-by-step explanation:
since (p,r) lies on y=x+b , it will satisfy the equation
=> r = p + b ......(1)
also, (2p,5r) lies of y=2x+b,it will satisfy the equation
=> 5r = 4p + b .....(2)
Subtracting (1) from (2),we get
4r=3p
Therefore,r:p=3:4
We know that 3/10*20=6 students are eating salads.
We also know that 3/5*20=12 students are eating sandwiches.
Assuming each person only eats one thing, there are 20-12-6=2 students eating lunches other than salads or sandwiches.