Five-fourths of a number is greater than three-fourths of the number by 7. Find the number.
- AOption (a)
8
- BOption (b)
12
- COption (c)
14
- DOption (d)
10
View answer & explanationHide answer & explanation
Correct answer
14
Why this answer is correct
Shortcut Trick
Let the common denominator be 4 units.
Difference between numerators = 5 units − 3 units = 2 units.
According to the question, 2 units corresponds to 7.
The full number (denominator) is 4 units.
4 units = 7 × 2 = 14.
∴ The correct answer is 14.
Alternate Method
Given:
Let the number be x.
⇒ (5/4)x − (3/4)x = 7
Calculations:
⇒ [(5 − 3) / 4] × x = 7
⇒ (2/4) × x = 7
⇒ (1/2) × x = 7
⇒ x = 7 × 2
⇒ x = 14
∴ The correct answer is 14.
Additional Information
Fractional Comparisons
When comparing fractions of the same base, the difference is simply the difference of the numerators divided by the common denominator.
Linear Equations
For any equation of form (a/c)x − (b/c)x = k, the value of x is calculated as x = (k × c) / (a − b).
