Sum of 2.3 + 7.7

The correct answer is: 10

Subtract 0.3 from 2.3 and compensate by adding 0.3 to 7.7
(2.3 - 0.3) + (7.7 + 0.3)
2 + 8 = 10

Arrange the numbers vertically and add:

Step 1: Add 3 and 7.

3+7=10

Here, the 1 is a carry.

Step 2:

2 + 7 + 1 = 10

The answer is 10.

The correct option is (b) 10