Question

Using an Arabic numeral, what is the
interval between the keys marked
below?

Answer 1

The interval between the marked keys is : ٨

From the drawing given, difference between two successive keys is 2 ;

This means;

• First marked key = 1 - 2 = -1
• Second marked key = 5 + 2 = 7

Interval between the two marked keys:

• Key 2 - Key 1

Evaluate :

7 - (-1) = 8

In arabic numeral : 8 = ٨