A can do 1 job in 10 min. means 1/10 job per min.
B can do 1/15 job per min.
together A&B can do 1/10+1/15 =1/6 job per min.
1/6 job they spend 1 min
1 spend 1x1/(1/6) = 6 min
1) mesure of an arc= R.Ф, where R is the radius & Ф the angle <span>IN RADIAN
32</span>°===>8π/45 OR 0.5585, So mes of Arc CD = 6x0.5585 = 3.35 cm
2) DAC = 31° & CAD =27° , these 2 angles being adjacent I can write that
Angle(DAC +CAB=DCB) ==>Angle DCB =(31°+27°=58°)
To remember that any vertex of an angle on the circles, its sides intercept an arc which mesure is twice the angle,
Hence since mes Angle DCB=58°, that means the ARC intercepted, namely DB has a length of 2x 58 = 116°
