Question

What should come in place of the question mark (?) in the given series? 250 210 175 145 120 ?

• A. 80
• B. 100
• C. 110
• D. 90

Answer 1

Answer:

B. 100

The number that should come in place of the question mark (?) is 100.

The series progresses by subtracting decreasing multiples of 5 at each step:

• 250 − 40 = 210

• 210 − 35 = 175

• 175 − 30 = 145

• 145 − 25 = 120

Following this exact pattern, the next number to subtract is 20:

• 120 − 20 = 100