You're right - it's D. Both ratios are equal to 1/2.
Answer:
The fraction 13/7 is a rational number. Both 13 and 7 are integers (whole numbers), so by definition, 13/7 is a rational number
Answer:
400 megabytes of data used will make the cost from either company equal.
Step-by-step explanation:
Given that:
Per month charges of Company A = $80
Charges of 100 MB = $5 = 
Let,
x be the number of MBs consumed.
y be the total charges.
y = 0.05x+80
Per month charges of Company B = $60
Charges of 100 MB = $10 = $0.1 per MB
y = 0.1x+60
For equal charges;
0.05x+80 = 0.1x + 60
80-60 = 0.1x-0.05x
20 = 0.05x

Hence,
400 megabytes of data used will make the cost from either company equal.
419979/3153=133.19981 that rounded is 133.2
419979/133.2=3152.9955 that rounded is 3153