The diameters of two given circles are as 3 : 4, and the sum of the areas of the circles is equal to the area of a circle whose diameter measures 30 c. Find the diameters of the given circles.

area of first circle = 22/7*(3x)²=22/7*9x²=198x²/7

area of second circle=22/7(4x)²=22/7*16x²=352x²/7

total area of circles = 198x²/7+352x²/7 = 550x²/7

area of third circle = 22/7*(30)²=22/7*900=19800/7

total area of circles = area of third circle

550x²/7 = 19800/7

550x²=19800

x²=19800/550=36

x = 6

diameter of circles = 6*3*,6*4*

=18,24