Angie sells blue and yellow balloons. for every 10 blue balloons that are sold, she sells 7 yellow balloons. if angie sells a total of 340 balloons, how many will be blue?

Angie sold 200 blue balloons out of the 340 balloons sold in total.

7 yellow balloons sold for every 10 balloon sold.

7 + 10 = 17 ; the percentage of 10 to the total number of balloons sold is:

10 / 17 = 0.588 * 100% = 58.80% or 59%

340 balloons sold * 59% = 200 blue balloons.

To check if its correct:

200 / 10 = 20 * 7 yellow balloons = 140 yellow balloons sold.

200 blue balloons + 140 yellow balloons = 340 balloons.

Ratio of blue to yellow is 10:7 so 10+17 is total and 10/17 are blue and 7/17 are yellow
if there's 340 balloons then 340×10/17= 200 are blue