Answer: Kristina sister's age = 15 years
Step-by-step explanation:
LET the sister's age be rep as x
SO that Kristina = 4/5 of x
Given that Kristina's age = 12 , Then her sister's age can be found using The equation
4/5 x X= 12
4/5 X =12
X = 5 X 12 / 4
=60/4=15
Kristina's sister's age = 15 years.
Answer:
Rate
Step-by-step explanation:
Rate is basically also a ratio. but it is the comparing of two different quantities with different units.
As ratio is comparing of same or identical quantities thus it has no units. But on the other hand as rate is the comparison of different quantities, thus it has units.
for example:
When i compare two quantities, 1st is a distance quantity and 2nd is a time quantity i.e.
20 meters : 15 seconds
thus the lowest form of this relationship will be:
4 meters : 3 seconds
when i write it in Decimal form it becomes :
Ans : 1.33 meters/second (Distance per unit time)
As this ratio have remaining units thus it is referred to as "RATE".
Area = π x radius²
dA/dr = 2πr
Average rate of change = (rate of change at one instant + rate of change at other instant)/2
= (2πr₁ + 2πr₂)/2
= (r₁ + r₂)π
Ai) 9π
Aii) 8.5π
Aiii) 8.1π
B) Instantaneous change:
(dA/dr) at (r = 4) = 2π(4)
= 8π
Answer:
113 R 6
Step-by-step explanation:
