Correct Answer - Option 4 : 1 and 3
Explanation:
- 18-4-1 High Speed Steel- It contains 18% Tungsten, 4% Chromium, 1% Vanadium
- Molybdenum High Speed Steel: 6% Molybdenum, 6% Tungsten, 4% Chromium, 2% Vanadium.
In ques., option no. 3 has 5Mo i.e., 5% Molybdenum but it is actually 6% Molybdenum.