Let's break this down step by step.
Step 1: Set up a variable.Let Machine B produce
x rods per hour.
Since Machine A produces
30% more than Machine B, Machine A produces
1.3x rods per hour.
Step 2: Write the equation.Together, they produce
x + 1.3x = 2.3x rods every hour.
In
2 hours, they produce
130 rods total, so:
2 ×
2.3x =
1304.6x =
130Step 3: Solve for x.x =
130 ÷
4.6x ≈
28.26 rods per hour (this is Machine B's rate)
Step 4: Find Machine A's rate.Machine A =
1.3 ×
28.26 ≈
36.7, which rounds to
37 rods per hour.
Answer: B — 37Quick sanity check: If Machine B makes about
28 rods/hour and Machine A makes
37 rods/hour, together that's about
65 rods/hour. In
2 hours, that's
130 rods. ✓
The most common mistake here is forgetting to account for the 2 hours. If you set x +
1.3x =
130 (without multiplying by
2), you'd get x ≈
56.5 and Machine A ≈
73.5 — which doesn't match any answer. That's your signal to re-read the problem:
130 rods in
2 hours means
65 rods per hour combined, not
130 per hour.