How many slices could he eat in half of an hour?
Mr. Takaya can eat three slices of pizza in five minutes. If he continues to eat at the same rate, how long will it take him to eat the whole pizza, which has twelve slices? How many slices could he eat in half of an hour?
Solution:
At constant rate, that is when the speed of eating pizza per unit time does not change: let that rate be, V = 3 slices/5 minute
the total pizza has 12 slices then V = 12 slices/ t, where t is the time needed to eat the whole pizza
substitute for V, 3 slices/5minutes = 12 slices/t
t= 12 slices/(3 slices/5minute), t = (12x5)/3 = 20 min
if t = half an hour = 30 minutes substitute in the above equation
30 = (slices x5)/3, 90 = slices x 5 , slices = 90/5 = 18 slices in half aan hour
another method to solve this is 12 slices --- 20 min
? 30 min
number of slices = (30x12)/20 = 18 slices
