David exercises every day. he spends 40% of his exercise time on the treadmill. if he uses the treadmill 40 minutes each day, how many minutes does he exercise each day?

David exercises 100 minutes each day.

Step-by-step explanation:

1. Let's review the information given to us to answer the question correctly:

David uses the treadmill 40 minutes each day = 40% of his exercise time

2. How many minutes does he exercise each day?

Let's use the Direct Rule of Three to answer this question:

Minutes        Percentage

40                    40

 x                      100

40 * x = 40 * 100

40x = 4,000

x = 4,000/40

x = 100

David exercises 100 minutes each day.

x =±sqrt(1/3)

step-by-step explanation:

x+4/6x=1/x

multiply each side by 6x to get rid of the fractions

6x*(x+4/6x)=1/x*6x

distribute

6x^2 +4 = 6

subtract 4 from each side

6x^2 +4-4 = 6-4

6x^2 =2

divide by 6

6x^2/6 = 2/6

x^2 = 1/3

take the square root of each side

sqrt(x^2) = ±sqrt(1/3)

x =±sqrt(1/3)

total amount of money that he should pay if he has not used his duty free exemption is $98

step-by-step explanation:

given a united states citizen returning to the states declares the following items at the customs office: 3 shirts at $8.50 each 2 dresses at $27.50 each 1 pair of gold cuff links at $17.50 per pair. we have to find how much he pay

cost of 3 shirts if one cost at $8.50 is

cost of 2 dresses if one cost at $27.50 is  

cost of 1 pair of gold cuff at $17.50

so, total amount of money that he should pay if he has not used his duty free exemption is   $25.5+$55+$17.50=$98