Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
The sum of radii of two circles is 140 cm and the difference of their circumferences is 88 cm. The diameters of the circles are
(a)77 cm, 63 cm
(b)150 cm, 120 cm
(c)154 cm, 126 cm
(d)160 cm, 120 cm
Answer
Answer (as printed): C
Explanation
We have : $R_{1}+R_{2}=140$ $$\text { And, } 2 \pi\left(R_{1}-R_{2}\right)=88 \Rightarrow R_{1}-R_{2}=\frac{88 \times 7}{2 \times 22}=14 \text {. }$$ Adding (i) and (ii) we get : $2 R_{1}=154$ or $R_{1}=77$. Putting $R_{1}=77$ in (i) we get : $R_{2}=63$. So, the diameters of the circles are 154 cm and 126 cm.
Explanation as extracted from the printed page; notation may be imperfect.