In the following question, select the missing number from the given series.
25, 144, 60, 81, 225, 135, 49, 289, ?
- A119
- B120
- C170
- D190
Solution & Step-by-step Explanation
Let us look at the terms grouped in sets of three:
First Group (25, 144, 60):
25
=5
144
=12
Multiplying these square roots together: 5×12=60
Second Group (81, 225, 135):
81
=9
225
=15
Multiplying these square roots together: 9×15=135
Third Group (49, 289, ?):
49
=7
289
=17
Multiplying these square roots together: 7×17=119
Therefore, the missing number is 119.
First Group (25, 144, 60):
25
=5
144
=12
Multiplying these square roots together: 5×12=60
Second Group (81, 225, 135):
81
=9
225
=15
Multiplying these square roots together: 9×15=135
Third Group (49, 289, ?):
49
=7
289
=17
Multiplying these square roots together: 7×17=119
Therefore, the missing number is 119.