Question

Sakshi can do a piece of work in $20$ days. Tanya is $25$% more efficient than Sakshi. The number of days taken by Tanya to do the same piece of work is:

• A. $15$
• B. $16$
• C. $18$
• D. $25$

Answer 1

The correct option is B $16$

Ratio of time taken by Sakshi and Tanya $=125:100=5:4$.(since $25$% more efficient)
Let's suppose Tanya takes $x$ days to do the work.
Therefore by proportion, $5:4::20:x$
$5\times x=4\times 20$
$\Rightarrow$ $x=16$ days.
Hence, Tanya takes $16$ days to complete the work.