The general way to work this out is to solve the general expression for
the remaining quantity versus half-life, using logarithms. But that's not
necessary with these numbers.
Look at the numbers:
-- 3 mg is 1/4 of 12 mg.
-- 1/4 is the product of (1/2) x (1/2).
-- So the 3 mg is what's left of 12 mg after 2 half-lives.
The 26 minutes must be two half-lives.
-- The half-life of that substance is 26/2 = <em>13 minutes</em>.
Go Maggie !
Answer:
(a) It costs $55 at Happy Fruiterer
(b) It will cost $49.64
(c) It is cheaper at Happy Fruiterer the second week
Step-by-step explanation:
Since Fruitz shop sells as 10% less than Happy Fruiterer at $50
10% more of $50 = 50 × 10/100 + 50
= $5 + $50 = $55
(a) n Kg of grapes will cost $55 at Happy Fruiterer
(b) if Happy Fruits discounts $55 by 5%, we will have
55 × 5/100 = 2.75
that is $55 - $2.75 = $52.25
If it is discounted further at 5% more the following week, we will have
$52.25 × 5/100 = $2.6125
≈ $2.61
Then the new price for the 2nd week is $52.25 - $2.61
= $49.64
(c) at the second wee of discounting, Fruitz shop still sells at $50 will Happy Fruiterer now see at $49.64. Therefore, it is cheaper at Happy Fruiterer
First add the biggest number like thousand together and the go in to the last numbers