Math Software Online: MathScore.com
  

Proportions 1 - Sample Math Practice Problems

The math problems below can be generated by MathScore.com, a math practice program for schools and individual families. References to complexity and mode refer to the overall difficulty of the problems as they appear in the main program. In the main program, all problems are automatically graded and the difficulty adapts dynamically based on performance. Answers to these sample questions appear at the bottom of the page. This page does not grade your responses.

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Complexity=5, Mode=fraction

Solve for n
1.  
24
40
= n
50
n:
2.  
7
35
= n
15
n:

Complexity=8, Mode=ratio

Solve for n
1.   49 : 56 = n : 48
n:
2.   36 : 24 = n : 20
n:

Complexity=10

Solve for n
1.   15 : 18 = n : 48
n:
2.   10 : 100 = n : 90
n:

Complexity=20

Solve for n
1.  
49
140
= n
180
n:
2.  
128
80
= n
50
n:

Answers

Complexity=5, Mode=fraction

Solve for n
#ProblemCorrect AnswerYour Answer
1
24
40
= n
50
 n:
Solution
First simplify the fraction on the left: 24/40 = 3/5
3
5
= n
50
Cross Multiplication: First fraction numerator × second fraction denominator = first fraction denominator × second fraction numerator.
3 × 50 = 5n.
Dividing both sides by 5,
n = 3 × 50 ÷ 5 = 30

Alternate Explanation:
First simplify the fraction on the left: 24/40 = 3/5
3
5
= n
50

n
50		 =
3
5

n
50		 = 3 × 10
5 × 10		 =
30
50
#ProblemCorrect AnswerYour Answer
2
7
35
= n
15
 n:
Solution
First simplify the fraction on the left: 7/35 = 1/5
1
5
= n
15
Cross Multiplication: First fraction numerator × second fraction denominator = first fraction denominator × second fraction numerator.
1 × 15 = 5n.
Dividing both sides by 5,
n = 1 × 15 ÷ 5 = 3

Alternate Explanation:
First simplify the fraction on the left: 7/35 = 1/5
1
5
= n
15

n
15		 =
1
5

n
15		 = 1 × 3
5 × 3		 =
3
15

Complexity=8, Mode=ratio

Solve for n
#ProblemCorrect AnswerYour Answer
149 : 56 = n : 48
n:
Solution
Begin by rewriting the ratios as fractions: '49 : 56 = n : 48' becomes

49
56
= n
48
Then simplify the fraction on the left: 49/56 = 7/8
7
8
= n
48
Cross Multiplication: First fraction numerator × second fraction denominator = first fraction denominator × second fraction numerator.
7 × 48 = 8n.
Dividing both sides by 8,
n = 7 × 48 ÷ 8 = 42
#ProblemCorrect AnswerYour Answer
236 : 24 = n : 20
n:
Solution
Begin by rewriting the ratios as fractions: '36 : 24 = n : 20' becomes

36
24
= n
20
Then simplify the fraction on the left: 36/24 = 6/4
6
4
= n
20
Cross Multiplication: First fraction numerator × second fraction denominator = first fraction denominator × second fraction numerator.
6 × 20 = 4n.
Dividing both sides by 4,
n = 6 × 20 ÷ 4 = 30

Complexity=10

Solve for n
#ProblemCorrect AnswerYour Answer
115 : 18 = n : 48
n:
Solution
Begin by rewriting the ratios as fractions: '15 : 18 = n : 48' becomes

15
18
= n
48
Then simplify the fraction on the left: 15/18 = 5/6
5
6
= n
48
Cross Multiplication: First fraction numerator × second fraction denominator = first fraction denominator × second fraction numerator.
5 × 48 = 6n.
Dividing both sides by 6,
n = 5 × 48 ÷ 6 = 40
#ProblemCorrect AnswerYour Answer
210 : 100 = n : 90
n:
Solution
Begin by rewriting the ratios as fractions: '10 : 100 = n : 90' becomes

10
100
= n
90
Then simplify the fraction on the left: 10/100 = 1/10
1
10
= n
90
Cross Multiplication: First fraction numerator × second fraction denominator = first fraction denominator × second fraction numerator.
1 × 90 = 10n.
Dividing both sides by 10,
n = 1 × 90 ÷ 10 = 9

Complexity=20

Solve for n
#ProblemCorrect AnswerYour Answer
1
49
140
= n
180
 n:
Solution
First simplify the fraction on the left: 49/140 = 7/20
7
20
= n
180
Cross Multiplication: First fraction numerator × second fraction denominator = first fraction denominator × second fraction numerator.
7 × 180 = 20n.
Dividing both sides by 20,
n = 7 × 180 ÷ 20 = 63

Alternate Explanation:
First simplify the fraction on the left: 49/140 = 7/20
7
20
= n
180

n
180		 =
7
20

n
180		 = 7 × 9
20 × 9		 =
63
180
#ProblemCorrect AnswerYour Answer
2
128
80
= n
50
 n:
Solution
First simplify the fraction on the left: 128/80 = 16/10
16
10
= n
50
Cross Multiplication: First fraction numerator × second fraction denominator = first fraction denominator × second fraction numerator.
16 × 50 = 10n.
Dividing both sides by 10,
n = 16 × 50 ÷ 10 = 80

Alternate Explanation:
First simplify the fraction on the left: 128/80 = 16/10
16
10
= n
50

n
50		 =
16
10

n
50		 = 16 × 5
10 × 5		 =
80
50
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