Multiply 40x7 then subtract that total you got from multiplying 40x7 with 420
40x7=160
420-160=260
260 pieces of wood were left.
Answer:
h=$65/13
Step-by-step explanation:
So he has $85
Now the remaining amount he needs is $65
And in every 13h he produces the $65
So to find his hourly earning is h=$65/13
So the equation is
h = $65/13
Answer:
You can fill 13.5 pages
Step-by-step explanation:
You would do 54 divided by 4 equals 13.5
Answer: 4 years
Step-by-step explanation:
A(0) has to be amount at start. Assume that's 5mg
Then A(t) = 5×(0.5)^(0.25t) = 5×2^(-t/4),
(also known as 5 exp(-λ t) with λ = ln(2)/4, incidentally).
We need to such that A(t) = 2.5mg, or 2^(-t/4) is 1/2, which happens when -t/4 is -1, or t is 4.
