Answer is
A) 48 kmh
In England, 30mph equals 48 Kmh
B) 43.75 mph
In another country, 70kmh equals 43.75 Mph
Step by step
From the graph we can see a definite coordinate point at (0, 0) and (50, 80)
To find rate (slope) we use slope form
y2 - y1 over x2 - x1
80 - 0 over 50 -0 = 80/50 = 1.6 rate
A) to change 30 mph to kmh multiply by the rate. 30 x 1.6 = 48 kmh
B) to change 70 kmh to mph, divide by 1.6 rate
70 รท 1.6 = 43.75 mph