Two lengths are in the ratio 7:4 and differ by 18 cm. Enter their combined length in cm.
الإجابة الصحيحة
66
الشرح
The difference of 3 ratio parts represents 18 cm, so one part is 6 cm and all 11 parts total 66 cm. Treating 18 cm as one part would triple both lengths and make their difference 54 cm instead.