How many `sigma and pi` bonds are present in each of the following molecules ?
(i) `HC -= C - CH = CHCH_3`
(ii) `C_6 H_12`
(iii) `CH_2 = C = CHCH_3`
(iv) `CH_2 = C = CH - CH = CH_2`

Explanation

To determine the number of sigma (σ) and pi (π) bonds in each of the given molecules, we will analyze each structure step by step.

### (i) HC ≡ C - CH = CH - CH₃

1. **Identify the Bonds:**
- The molecule has a triple bond (C≡C) and a double bond (C=C).
- The remaining bonds are single bonds (C-H and C-C).

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