Answer:
Step-by-step explanation:
If the water level rises 17 centimeters every 7 minutes, then (21, y)means that after, 21 minutes, it would have rise by y centimeters, using the equality postulate:
17cm = 7min
y = 21min
Cross multiply
7y = 21*17
y = 21*17/7
y = 3*17
y = 51cm
Hence the value of y is 51
