Brain Test Level 463
Question:
What is the next number in the sequence: 10, 20, 30, 40, ?
Solution:
The sequence increases by 10 each time, so the answer is 50.
However, the '5' key is missing from the input keypad.
Drag the '1' key and the '4' key together on the screen. They will merge to form the '5' key.
Now input 50.
DIFFICULTY
Medium
PRO TIP
The answer is 50, but the '5' key is missing. Maybe you can construct it from other numbers?