Question
A and B can do a piece of work in 30 days and 40 days,
respectively. They began the work together but after a certain time, A leaves off and B completed the remaining work in 25 days. After how many days did A leave?Solution
Let, after x days A leave. Let the total work is the 120 units (LCM of 30 and 40) Efficiency of A is 120 / 30 = 4 units The efficiency of B is 120/40 = 3 units So, after x days they both work together. According to the question, (4+3) x x + 25 x 3 = 120 Â 7x + 75 = 120 7x = 45 Â x = 45/7 days =6(3/7)days.
Sum of three positive numbers is 126. If the ratio of the first and second number is 4:5, respectively while difference between the first and third num...
Three natural numbers X,Y,Z are pairwise co-prime and satisfy the following conditions, the least common multiple (LCM) of X and ...
Find the sum of all natural numbers less than 500 which are divisible by 7.
Sahil can make a toy in 3 hrs, 25 minutes and 13 seconds. How much time he will take to make 8 such toys?
Find the smallest 4-digit number which is exactly divisible by 6, 9 and 15.
- Calculate the largest 5-digit number which is divisible by ‘64’
What is the average of all the prime numbers which are less than 35?
'M' is the largest three-digit number that leaves 3 as a remainder when divided by 9, 12 and 5, Find the sum of digits of 'M'.
The square of the sum of two numbers is 784. The sum of squares of these numbers is 520. Find their product.
Relevant for Exams:
