Answer:
the normal heart rate of the grizzley bear = 12.5 beats per minute
Step-by-step explanation:
let the normal heart rate = x
hibernating heart rate = 20% of normal value = x - 10
20% of x = x - 10
20/100 of x = x - 10
0.2 × x = x - 10
0.2x = x - 10
x - 0.2x = 10
0.8x = 10
x = 10 ÷ 0.8 = 12.5 beats per minute