Answer:
The answer is B.
Step-by-step explanation:
Any percentage is a number divided by 100 . So 0.4%=0.4100 . Dividing 0.4 by 100 gives 0.004 .
Answer:
Coupon B
Step-by-step explanation:
Given



Required
Which coupon is better
From the question, we have:


Coupon B means that:



By comparison:
Coupon B gives him a better buy because: 
Answer:
15 and 5 hours.
Step-by-step explanation:
Call x the time taken by the first chap, and y the second.

Let's divide by 5 and play with the LHS of the first equation a bit:
we know how much x+y is ( first equation!) let's solve.
At this point it's easy to check that 
(9.6 x 10^3) (6.7 x 10^2)
(9,600) (670)
6,432,000
6.432 x 10^6
Answer:
6.432 x 10^6