The ages of two siblings are in the ratio 4:5. If the sum of their ages is 72, what is the age of the older sibling? (2023)
Practice Questions
1 question
Q1
The ages of two siblings are in the ratio 4:5. If the sum of their ages is 72, what is the age of the older sibling? (2023)
40
36
32
28
Let the ages be 4x and 5x. Then, 4x + 5x = 72, leading to 9x = 72, so x = 8. The older sibling's age is 5x = 40.
Questions & Step-by-step Solutions
1 item
Q
Q: The ages of two siblings are in the ratio 4:5. If the sum of their ages is 72, what is the age of the older sibling? (2023)
Solution: Let the ages be 4x and 5x. Then, 4x + 5x = 72, leading to 9x = 72, so x = 8. The older sibling's age is 5x = 40.
Steps: 8
Step 1: Understand that the ages of the two siblings are in a ratio of 4:5. This means if one sibling's age is 4 parts, the other sibling's age is 5 parts.
Step 2: Let the age of the first sibling be 4x and the age of the second sibling be 5x, where x is a common multiplier.
Step 3: Write an equation for the sum of their ages: 4x + 5x = 72.
Step 4: Combine the terms on the left side of the equation: 9x = 72.
Step 5: Solve for x by dividing both sides of the equation by 9: x = 72 / 9.
Step 6: Calculate the value of x: x = 8.
Step 7: Find the age of the older sibling by calculating 5x: 5 * 8 = 40.
Step 8: Conclude that the age of the older sibling is 40.
