Question
A piece of work consists of 360 identical units. A can
do (x + 4) units per day and B can do (x − 2) units per day. They work together for 9 days and the remaining work is completed by A alone in 5 more days. In how many days can B alone complete the entire work?Solution
ATQ, Total work = 360 units A’s speed = (x + 4) units/day B’s speed = (x − 2) units/day Work done in first 9 days by A and B together = (x + 4 + x − 2) × 9 = (2x + 2) × 9 = 18x + 18 Remaining work done by A in 5 days = (x + 4) × 5 = 5x + 20 Total work = (18x + 18) + (5x + 20) = 360 23x + 38 = 360 23x = 322 x = 14 So A’s speed = 14 + 4 = 18 units/day B’s speed = 14 − 2 = 12 units/day Time taken by B alone = 360 / 12 = 30 days
Which of the following matrices is both symmetric and skew-symmetric?
A ladder leaning against a wall makes an angle of 60° with the ground. If the ladder is 10 meters long, how high up the wall does it reach?
69 73 64 80 ? 91
Integrated circuits are made up of:
The sum of the ages of a father and his son is 50 years. After 5 years, the father's age will be twice that of his son. What are their present ages?
67.2, 8.4, 1.2, 0.2, 0.04, ?
Calculate the simplified value of the given expression:
...
(5 + 13 of 7 - 5.25 of 8 + 63) ÷ 18What is the total number of packages delivered in February across all regions, and what percentage does it contribute to the total packages delivered in...
315 people went to a park. The number of men is 25 more than the number of women and the number of adults is 15 more than the number of children. How ma...
