How to sumif with condition = blank cell?

[Poey]

Mode Speed
a 10
5
a 70
b 150
6
c 8

How do I get the sumif for mode = "blank" if I am not allowed to enter anything to the blank cell?

thanks,
Poey

[ramananhrm]

Use this function with Ctrl+Shift+Enter
=SUM(IF($B$2:$B$7="",$A$2:$A$7))

[NeedForExcel]

What is your Sum if condition though?

[Poey]

Let me put in the raw data and the sumif condition as below:
Raw data
Mode Speed
a 70
5
a 70
b 150
6
c 8

Mode Total speed
a 140
b 150
c 8
? how to use sumif to get the answer =11?

[Rambo4711]

Here is my solution:

[ramananhrm]

I have tried in a different way.

Regards