You can cheat in this case: Treat it as a 3/4.
For example: First beat would be triplet + triplet + quarter note (1) ti-ti-ti + 2) ti-ti-ti + 3) ta. Every of these with the same duration )😄

@Ray Towers I dont reallly get it T_T but thank you so much 3
😭😢

A triplet is 3 notes played within the same time, as you would usually just play two notes of the same value.

This means that an 8th note triplet is 3 notes played equally split up in time of just two 8th notes.

To get a rhythmic feeling for it, you might just look up some videos on YouTube about triplets.

If you understand previous explanations and still don't know how to tap the exercise displayed on the pic you attached, @Minh Phương , it could be because it's such an awkward and confusing example of a 6/8 time signature. If you're not familiar with these signatures (6/8, 9/8 and 12/8), I recommend doing some research about them.

A 6/8 bar is formed by 2 beats (like 2/4), with each beat subdivided in 3 eighth notes. Its generic 'groove' would be '1,2,3', '1,2,3', with the accents on the '1'. Think of 'Everybody Hurts' by R.E.M., 'Never Tear Us Apart' by INXS or 'Only You' by The Platters. Those might also be considered as 12/8 (4 beats instead of 2).

So, in this exercise, the natural distribution in groups of 3 is completely ignored (sorry, ToneGym, but it's true!) and what's more weird: they ask you to replace '1,2' and '3,1' with triplets! My advice in this case would be the 'cheating' tip by @Ray Towers in order to advance this level ASAP and take your time to research and understand compound signatures later...

dadada dadada doom | doom dadada doom

DoDoom Tsssssss...😂

OMG thanks guys !!!!! There's a lots help hereeee 😍

Yes lots of them are hard. I’m using tone gym alongside other ear training apps, studying the theory and my own playing of guitar. A lifetime of learning.

With triplets I count like this: higgelty piggelty
So, I’d count the example on your screen shot as:
Higgelty piggelty boom, boom higgelty boom
It’s from an old English nursery rhyme. You might have something similar in your language.