Changes

The condition of the problem is the following:

Let's first express all the variables, because we need to find the number of donuts. It will be d. We have:

We use the bar to see the connection between muffins and scones.

But now we need to add donuts to see the big picture.

But according to the condition, it is important for us that the total amount is 170. To do this, we combine everything with a bracket and put the total amount.

We got a picture, now we need to draw a task question. That is, find the number of donuts.

Together we get 10 bars. From here we can find out that 1 bar is equal to 17 - because 170 (total) we divide by one item. If we have three donut bars, then we multiply 17 by 3 and get 51.