To solve the expression \((7/30 + 1/2 + 4/15) : (49/50 - 14/25 - 2/5)\), we can start by simplifying both the numerator and the denominator separately.
Step 1: Simplifying the Numerator
The numerator is \(7/30 + 1/2 + 4/15\).
Find a common denominator. The least common multiple (LCM) of \(30\), \(2\), and \(15\) is \(30\).
Rewrite each fraction with the common denominator:
- \(1/2 = 15/30\)
- \(4/15 = 8/30\)
Add the fractions:
\[ 7/30 + 15/30 + 8/30 = (7 + 15 + 8)/30 = 30/30 = 1 \]
So, the numerator simplifies to \(1\).
Step 2: Simplifying the Denominator
The denominator is \(49/50 - 14/25 - 2/5\).
Find a common denominator. The LCM of \(50\), \(25\), and \(5\) is \(50\).
Rewrite each fraction with the common denominator:
- \(14/25 = 28/50\)
- \(2/5 = 20/50\)
Subtract the fractions:
\[ 49/50 - 28/50 - 20/50 = (49 - 28 - 20)/50 = 1/50 \]
So, the denominator simplifies to \(1/50\).
Step 3: Final Calculation
Now we can evaluate the expression:
\[ 1 : (1/50) = 1 \times (50/1) = 50 \]
Thus, the final result is:
\[ \boxed{50} \]