**You can solve this math equation using your brain. Solve the puzzles and improve your logical thinking.**

### Puzzle:

1 + 5 = 18

2 + 7 = 27

3 + 9 = 36

5 + 10 = 45

4 + 20 = ?

**Options:**

A. 70

B. 72

C. 75

D. 68

**Answer:** **B. 72**

**Solution:**

**1 + 5 = 6 * 3 = 18**

**2 + 7 = 9 * 3 = 27**

**3 + 9 = 12 * 3 = 36**

**5 + 10 = 15 * 3 = 45**

**4 + 20 = 24 * 3 = 72**