Running at the same constant rate, 6 identical machines can produce a total of 270 bottles per minute. At this rate, how many bottles could 10 such machines produce in 4 minutes?
P and Q need 8 days to complete a work. Q and R need 12 days to complete the same work. But P, Q and R together can finish it in 6 days. How many days will be needed if P and R together do it?
A.
7 days
B.
8 days
C.
9 days
D.
10 days
Answer: Option B
Explanation:
Let work done by P in 1 day = p work done by Q in 1 day =q Work done by R in 1 day = r p + q = 1/8 —(1) q + r= 1/12 —(2) p+ q+ r = 1/6 —(3) (3) – (2) => p = 1/6 – 1/12 = 1/12 (3) – (1) => r = 1/6 – 1/8 = 1/24 p + r = 1/12 + 1/24 = 3/24 = 1/8 => P and R will finish the work in 8 days
10 men can complete a work in 7 days. But 10 women need 14 days to complete the same work. How many days will 5 men and 10 women need to complete the work?
A.
4 days
B.
5 days
C.
6 days
D.
7 days
Answer: Option D
Explanation:
Work done by 10 men in 1 day = 1/7 Work done by 1 man in 1 day = (1/7)/10 = 1/70 Work done by 10 women in 1 day = 1/14 Work done by 1 woman in 1 day = 1/140 Work done by 5 men and 10 women in 1 day = 5 × (1/70) + 10 × (1/140) = 5/70 + 10/140 = 1/7 => 5 men and 10 women can complete the work in 7 days
