The least amount he should pay for the bill is:

        19,50 x 80%=15,6(dollars)

The least amount he should pay for the tax is:

        15,6 x 6%=0,936(dollars)

The least amount he should pay fỏr the tip is:

        19,50 x 20%=3,9(dollars)

We can do this by using Pascal's triangle. The numbers from the tenth row of the triangle (corresponds to the number in the subsets) is:

1    10   45   120   210   252   210   120   45   10   1

(0)  (1)  (2)   (3)   (4)    .................................  (9)  (10)

Because the question asks about odd number of elements so there are:

10+120+252+120+10=512( subsets)

ANSWER: 512 subsets

There are all: 6⋅6=36(ways) for the two dice to roll.

The possible ways of the two dice are: 6-5 ; 5-4 ; 4-3 ; 3-2 ; 2-1 and reverse the order

So the probability is: \(\dfrac{5.2}{36}=\dfrac{10}{36}=\dfrac{2}{18}\)

The total view of the 5 people is: 5.122.890.142 + 7.818.125.465 + 11.789.267.938 + 13.466.208.534 + 14.492.168.647 = 52.688.660.906 (views)

We have: 54 * 3 = 162 so the possible number is 162.

There are total: 10⋅9:2=45(matches) matches in the tournament so there are 45 wins and 45 loses.

If there are 6 players have 7 or more wins, there are: 6⋅7=42(wins) , so there are 42 loses left but there must have 6 more lose (the battles together) so it is unsatisfy

But if there are 5 players then it will satisfy the question.

Hence, the answer is 5 players.

a=GCF(72;48)=24;b=GCF(108;144)=36a=GCF(72;48)=24;b=GCF(108;144)=36

LCM(a;b)=72

There are 26 letters in the English alphabet

There are 2 choices to choose the first letter

There are 24 choices to choose each of the last 3 letters

The answer is : 2 x \(24^3\) = 27648

The distance a hare runs in an hour is: 1⋅60=60(m)

The distance a tortoise crawls in an hour is: 1⋅60⋅60=3600(cm)=36(m)

So the distance the hare travels further than the tortoise is: 60−36=24(m)

There are: \(\left(24.60\right).150=2160000=2,16.10^5\)more people are on Earth every day.

The height of the sixth bounce is: 5⋅80%⋅80%⋅80%⋅80%⋅80%=1,6384≈1,6(ft)

ANSWER: 1,6 ft

Because the head size is 15% then the total size of body and foot is: 100% - 15% = 85%

The percentage of body size is: \(\dfrac{85}{5+7}.5=\dfrac{425}{12}\approx35\%\)

The boy has covered only two-fifth way => The total speed of the girl and the moving walkway is: \(\dfrac{5}{2}\)

So the ratio of the walkway's rate to the girl's rate (sililar to the boy's rate) is: \(\dfrac{5}{2}-1=\dfrac{3}{2}=3:2\)

ANSWER: 3:2

The ratio of the area of the second and the first pasture is: \(\left(8:2\right)^2\)=16

So the area of the second pasture is: 25⋅16=400(hectares)

ANSWER: 400 hectares

The fraction is:\(\left(1-\dfrac{2}{5}\right):2=\dfrac{3}{10}\)

The number of potatoes which can feed 5 people for 2 days is :

\(\dfrac{5}{12}.48=20\)

The number of potatoes which can feed 5 people for 3 days is :

\(\dfrac{3}{2}.20=30\)

+ 2x−1≥0⇔x≥122x−1≥0⇔x≥12

2x−1>x+3⇔2x−x>3+1⇔x>42x−1>x+3⇔2x−x>3+1⇔x>4

+ 2x−1<0⇔x<122x−1<0⇔x<12

1−2x<x+3⇔1−3<x+2x⇔3x>−2⇔x>−231−2x<x+3⇔1−3<x+2x⇔3x>−2⇔x>−23

So, x>4x>4 or −23<x<12