Question

Find missing number in series 81,87,107,147,?,331

Answer 1

Answer:

The given sequence:

81, 41 , 42, 64.5, ? , 330

To find, the value of missing number (?) = ?

The pattern follow:

× 0.5 + 0.5, × 1 + 1, × 1.5 + 1.5, × 2 + 2, × 2.5 + 2.5, .....

41 = \dfrac{81}{2} +0.5=40.5+0.5=41

2

81

+0.5=40.5+0.5=41

42 = 41\times 1+1=41+1=4241×1+1=41+1=42

64.5 = 42 × 1.5 + 1.5 = 63 + 1.5 = 64.5

? = 64.5 × 2 + 2 = 129 + 2 = 131

330 = 131 × 2.5 + 2.5 = 327.5 + 2.5 = 330

∴ Missing number (?) = 131

Thus, the missing number is equal to 131