Math Problem Statement

Solve mathematical problems involving fractions, ratios, and simplifications.

Solution

Let's solve the questions from the worksheet one by one.

Q1. What should be added to 385\frac{38}{5} to get 18?

We are looking for a number xx such that: 385+x=18\frac{38}{5} + x = 18 To solve for xx, subtract 385\frac{38}{5} from both sides: x=18385x = 18 - \frac{38}{5} First, convert 18 to a fraction with denominator 5: 18=90518 = \frac{90}{5} Now subtract: x=905385=90385=525x = \frac{90}{5} - \frac{38}{5} = \frac{90 - 38}{5} = \frac{52}{5} Thus, x=525x = \frac{52}{5}.


Q2. Milk is sold at rupees 674\frac{67}{4} per litre. Find the cost of 325\frac{32}{5} litres of milk.

We are asked to find the total cost for 325\frac{32}{5} litres of milk when the cost per litre is 674\frac{67}{4}. The total cost is: Total cost=325×674\text{Total cost} = \frac{32}{5} \times \frac{67}{4} Multiply the numerators and the denominators: 32×675×4=214420\frac{32 \times 67}{5 \times 4} = \frac{2144}{20} Simplify: 214420=107.2\frac{2144}{20} = 107.2 Thus, the cost of 325\frac{32}{5} litres of milk is ₹107.2.


Q3. By what number should 569\frac{56}{9} be multiplied to obtain 314\frac{3}{14}?

We need to find a number xx such that: 569×x=314\frac{56}{9} \times x = \frac{3}{14} To solve for xx, divide both sides by 569\frac{56}{9}, which is the same as multiplying by the reciprocal 956\frac{9}{56}: x=314×956=3×914×56=27784x = \frac{3}{14} \times \frac{9}{56} = \frac{3 \times 9}{14 \times 56} = \frac{27}{784} Thus, the number is 27784\frac{27}{784}.


Q4. List five rational numbers between 45-\frac{4}{5} and 23-\frac{2}{3}.

Convert both numbers to a common denominator for easy comparison. The LCM of 5 and 3 is 15.

  • 45=1215-\frac{4}{5} = -\frac{12}{15}
  • 23=1015-\frac{2}{3} = -\frac{10}{15}

We now look for five rational numbers between 1215-\frac{12}{15} and 1015-\frac{10}{15}. Some possible choices are: 1115,121150,122150,111140,12.515-\frac{11}{15}, -\frac{121}{150}, -\frac{122}{150}, -\frac{111}{140}, -\frac{12.5}{15} This list includes numbers between 1215-\frac{12}{15} and ( -\frac111--- not

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Fractions
Rational Numbers
Multiplication of Fractions
Rational Number Ordering
Simplification of Expressions

Formulas

Addition of Fractions: a/b + c/d = (ad + bc) / bd
Multiplication of Fractions: a/b * c/d = (a*c) / (b*d)
Simplification of Complex Fractions
Cost Calculation Formula: Total cost = Price per unit * Quantity

Theorems

Basic properties of rational numbers and arithmetic operations

Suitable Grade Level

Grade 7