SSC CGL 202011)Sixteen men can finish a work in 8 days. Eight men and nine women working together can finish the same work in 10 days. In how many days will twenty women finish the same work?
12
Let one man can finish work in m days & one woman finish work in w days. then work done by 1 man in 1 day is 1/m .
and work done by 16 men in 8 days = 1 .
\(\therefore{16\times8\over m}=1\);
also, \({8\times10\over m}+{9\times10\over w}=1\); Solving above, m = 128 days, w = 240 days;
Let 20 women finish work in x days = \({20\times x\over 240}=1\); ⇒ x = 12 days
SSC CGL 202012)To complete a certain task. X is 40 % more efficient than Y, and Z is 40% less efficient than Y. Working together, they can complete the task in 21 days. Y and Z together worked for 35 days. The remaining work will completed by X alone in:
5 days
Efficiency of X = 140% of Y = 1.4Y;
Efficiency of Z = 60% of Y = 0.6Y;
Efficiency of X, Y and Z = 1.4 : 1 : 0.6 = 7 : 5 : 3;
They can complete the task in 21 days so,
\(Total \space work = sum\space of\space efficiency\space ratio \times times = (7 + 5 + 3) \times 21 = 315\);
Y and Z together worked for 35 days so,
Work done by Y and Z = \((5 + 3) \times 35 = 280\);
Remaining work = 315 - 280 = 35;
Remaining work complete by X = work/efficiency = 35/7 = 5 days