A is 30% more efficient than B. How much time will they working together take to complete a job which A alone could have done in 23 days?	Pick.
A) 11 B) 13 C) 20 3/17 D) 14 E) None of these
Explanation:   Ratio of times taken by A and 13= 100:130 =10:13   suppose 13 takes x days to work the 10:13::23:x =&gt;x=23 x 13/10 = 299/10   A’s one day work = 1/23 and 13’s is 10/299   Then A+13 ‘s work = 1/23 + 10/299 = 23/299 =1/13 =&gt; 13 days   Answer: Option 13
<result>B</result>
A is 30% more efficient than B. How much time will they working together take to complete a job which A alone could have done in 23 days?