Anonymous
Anonymous asked in Science & MathematicsMathematics · 8 years ago

# SAT MATH questionnnn....helpp? 10 pts?

1. A baseball team won 54 more games than it lost. If the team played a total of 154 games and there were no ties, how many games did the team win?

(A) 50

(B) 98

(C) 100

(D) 102

(E) 104

2. In a marathon, runners who finish 1st through 75th receives gift certificates; those who finish 76th and higher do not. If 312 runners participated in the race, how many did NOT receive gift certificates?

(A) 75

(B) 76

(C) 236

(D) 237

(E) 238

3. A watch loses x minutes every y hours. At this rate, how many hours will the watch lose in one week?

(A) 7xy

(B) 2x / 5y

(C) 5y / 2x

(D) 14y / 5x

(E) 14x / 5y

4. Allie has three fewer than twice the number of coins that Jonathan has. If Jonathan gave 2 coins to Allie, she would have three times as many coins as he would. How many coins does Allie have?

(A) 2

(B) 3

(C) 5

(D) 7

(E) 9

Answer: D. I need the EXPLAINATION.

Relevance

1) let w and L be games won and lost. Then w = 54 + L. Total games is w + L = 154. Since we want to know how many games won, we need to eliminate the L.

w - L = 54 just subtracted L on both sides

w + L = 154

2w = 208, div by 2

w = 104

2) This one is just 312 runners - 75 certificates = 237

3) This is a proportion. x lost minutes / y hours = answer / hours in a week

First find out how many hours in a week. 7 days * 24 hours = 168

cross mult and get 168x = y*answer

This gives it to us in minutes where the answer is in hours. Minutes * (1 hour / 60 minutes) gives us an answer in hours, so multiply by 1/60

168x / 60y and reduce to lowest terms 12x / 5y

4)Let A be the number of coins Allie has now and J be the number he has now.

First situation is as follows

A = 2J - 3

Second situation

A+2 = 3*(J-2)

or A = 3(J-2)-2

Set them equal to each other to get

2J - 3 = 3(J-2)-2

2J - 3 = 3J - 6-2

5 = J

A = 2*5-3

A = 7