Question
Sum of squares of three consecutive numbers is 770. Find
the sum of first and third number.Solution
Let the numbers be (x – 1), x and (x + 1) => (x – 1)2 + x2 + (x + 1)2 = 770 => x2 – 2x + 1 + x2 + x2 + 2x + 1 = 770 => 3x2 = 770 - 2 => x2 = 768/3 => x2 = 256 => x = 16 Required sum = (16 – 1) + (16 + 1) = 32
- Vikas does 65% of a job in 39 days, while Suman does 40% in 40 days. Vikas worked for 18 days and left. Calculate how many days Suman would need to wrap up...
Komal and Seema individually can complete a task in ‘5a’ hours and ‘7a’ hours respectively. If they together can complete (4/5)th of the work in...
'A' and 'B' alone can complete a work in 9 days and 18 days, respectively. Find the time taken by them to complete the work if they work on alternate da...
Efficiency of A is 25% more than B and B takes 30 days to complete a piece of work. A started the work alone and then B joined him 4 days before actual ...
A group of workers was put on a job. From the second day onwards, 1 worker left work everyday. If no worker was left when 52% of the work gets complete...
Ajay, Bablu and Chirag can complete a certain work in 21, 28 and 15 days respectively. Ajay and Chirag started the work while Bablu joined them after 5 ...
A can complete a job in 20 hours. B alone can complete the same job in 15 hrs. A work for 9 hrs and then the remaining job is completed by B. How many h...
Ananya and Riya can complete a task in 20 hours and 40 hours respectively. Ananya works alone for 10 hours and then Riya finishes the remaining task. Ho...
- Alex and Ben can complete a job individually in 14 days and 21 days, respectively. If they take turns to work one day each, beginning with Alex, how long w...
- Pipes X and Y can fill a tank in 45 minutes and 60 minutes respectively. Another pipe Z can empty the tank in 1 hour 30 minutes. If X and Z are opened firs...
Relevant for Exams:
