Seven softball bats and one tennis racquet cost $120. Three softball

Question

Seven softball bats and one tennis racquet cost $120. Three softball bats and three tennis racquets cost $180. How much does one softball bat cost?

A. $12 
B. $11 
C. $10 
D. $9 
E. $8

HungNguyen · Answer

Let's call the softball bats price = x
the tennis racquet price = y

We will have :

7x + y = 120
and 
3x + 3y = 180

so we will have to solve this set of equations

sorry because I have just join gmatclub for about 3 or 4 days so I wasn't allowed to post the image

(1)
7x + 1y = 120 
3x + 3y = 180

(2)
21x + 3y = 360
3x + 3y =180

(3)
18x = 180
3x + 3y = 180

(4)
x = 10
3x + 3y = 180

(5)
x = 10
3*10 + 3y = 180

(6)
x = 10
30 + 3y = 180

(7)
x = 10
3y = 150

(8)
x = 10
y = 50

so the result:
x = 10
y = 50
so the softball bats cost $10 each
and the tennis racquet cost $50 each

=> the answer is C ($10)

Sorry for my bad English

vivekkumar987 · Answer

7B+1R=120
3B+3R= 180

solving equ:
(x 3) 21B+3R=120*3
 3B+ 3R=180

when we solve ,we get B =10

Kurtosis · Answer

7s + t = 120 --- (1)
3s + 3t = 180 --> s + t = 60 --> t = 60 - s

Substitute t in (1)
7s + 60 - s = 120
6s = 60
s = 10

Answer: C

chetan2u · Answer

Hi,

another method..
1)  3B +3T = 180 ...........
or......... B+T=120...(i)

2)  7B+T=210.......(ii)..

subtract (i)from it...

7B+T - (B+T) = 120 - (60)............7B+T-B-T=60.......................6B=60.................B=10

C

HarisinghKhedar · Answer

Hi friend, welcome to this club.

I wanted to add my 2 cents. Whenever you've system of equations, try always to simply them first. In step 2, you could have simply reduced the second equation first and then cancel out y from both equations. Likewise, you can MINIMIZE required work.

Also, always try to isolate the target variable (in this case, x). Your sole focus then is to remove y. I'm sure you'll be better put with this strategy.

Cheers. All the best.

Posted from my mobile device

HungNguyen · Answer

Thanks for the advice

I will keep it in my mind

Divyadisha · Answer

7B + T= 120 or 21 B+3T= 360-------- 1

3B + 3T= 180-------2

Solving equation 1 and 2

18 B= 180 
B= 10

Ankit73 · Answer

As per the question

7S + T = 120 and 3S + 3T = 180.

Solving 3S + 3 T = 180, we get S+T = 60.

Hence, 7S + T =120
 , 6S + S + T =120
 , 6S = 120 - 60
 , S = 10

Answer C.

Seven softball bats and one tennis racquet cost $120. Three softball

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