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**77) **A PERT network has three activities on critical path with mean time 3, 8 and 6 and standard deviations 1, 2 and 2 respectively. The probability that the project will be completed in 20 days is

**Answer is:**

## 0.84

**Related KPCL AE Mechanical Question Paper - 2018 with Answer Key**

**Answer is:**

### Torsional vibrations

**Answer is:**

### Gravitational force is less than the upthrust of the liquid

**Answer is:**

### All of these

**Explanation:**

The tool may fail due to

* cracking at the cutting edge due to thermal stresses

* chipping of the cutting edge

* plastic deformation of the cutting edge