Correct Answer - Option 4 : 73.5

**Calculation:**

The logic behind the given series is as follows:

236 – 2.5 = 233.5

233.5 – 7.5 = 226

226 – 32.5 = 193.5

193.5 – 52.5 = 141

Now, the pattern in the difference taken:

2.5, 7.5, 32.5, 52.5, ?

2.5 × 3 = 7.5

2.5 × 13 = 32.5

Difference between 13 and 3 = 10

2.5 × 21 = 52.5

Difference between 21 and 13 = 8

so, next term : 2.5 × (21 + 6) = 2.5 × 27 = 67.5

Then, next term in the given series is = 141 – 67.5 = 73.5

**∴ The value of '?' is 73.5.**