Question
Two circles with centers B and D have radii DA = 8 cm
and BC = x cm, respectively. AC is tangent to both circles. If DB and AC intersect the point E, AE = 12 cm, and EC = 18 cm, then find the value of x (in cm).Solution
AD ⊥ AC and BC ⊥ AC ∠DAE = ∠BCE = 90° In △ DAE and △ BCE ∠DAE = ∠BCE = 90° ∠AED = ∠BEC (Vertical angle) △ DAE ~ △ BCE (By AA similarity) By C.P.C.T = AE/EC = AD/BC = 12/18 = 8/BC  BC = (18×8)/12 =144/12 x= 12cm  The correct answer is 12 cm.
58   83   133   ?    308    433
60, 100, 160, 240, ?, 460
In each of the following number series, one term is missing. Find the missing term.
7, 14, 28, 56, 112, ?
12, 19, 33, ?, 117
4, 12, 36, 108, ?, 396
945, 1890, ?, 504, 144, 32
What will come in place of the question mark (?) in the following series?
11, 13, 19, ?, 51, 81
Find the missing number, in the given number series.
60, 150, ?, 450, 450, 225
31Â Â Â 40Â Â Â 51Â Â Â 64Â Â Â 79Â Â Â Â ?
- What will come in place of the question mark (?) in the following series?
13, 15, 18, 23, 30, ?
Relevant for Exams:
