Show that the sum of all terms of an A.P. whose first term is a
Question 7: Show that the sum of all terms of an A.P. whose first term is a, the second term is b and the last term is c is equal to . … Read more
Question-Answer
If the sum of first ‘p’ terms of an A.P. is ‘q’
Question 6: If the sum of first ‘p’ terms of an A.P. is ‘q’ and the sum of first ‘q’ terms is ‘p’ ; then show that the sum of the first (p + q) terms is {-(p + q)}. Solution: Let the first term of an A.P. = a Common difference of A.P. = … Read more
If the sum of first m terms of an A.P. is some as
Question 5: If the sum of first m terms of an A.P. is some as the sum of its first n terms, show that the sum of its first (m + n) terms is zero. … Read more
The digits of a positive number of three digits are in A.P.
Question 4: The digits of a positive number of three digits are in A.P. and their sum is 15. The number obtained by reversing the digits is 594 less than the original number. Find the number. Solution:- Let the required three digits in A.P. of three digit number = (a – d), a, (a + … Read more
If the sum of the first 6 terms of an A.P. is 36
Question 3: If the sum of the first 6 terms of an A.P. is 36 and that of the first 16 terms is 256, find the sum of the first 10 terms. [CBSE 2016, 13, 12] Solution: Let the first term of A.P. = and Common difference = d Given, ——(i) Again, ——(ii) … Read more
The first term of an A.P. is -5 and the last term is 45
Question 2: The first term of an A.P. is -5 and the last term is 45. If the sum of the terms of the A.P. is 120, then find the number of terms and the common difference. [CBSE 2019, 17, … Read more
Ramkali would require Rs 5000 for getting her daughter
Question 1: Ramkali would require Rs 5000 for getting her daughter admitted in a school after a year. She saved Rs 150 in the first month and increased her monthly by Rs 50 every month. Find, if she will be able to arrange the required money after 12 months. Which value is reflected in her … Read more
In a flight of 600 km an aircraft was slowed due to
Question 5:- In a flight of 600 km an aircraft was slowed due to bad weather. Its average speed for the trip was reduced by 200km/hr and time of flight increased by 30 minutes. Find the original duration of flight. [CBSE 2020] Solution :- Let the actual speed of flight = ‘x’ km/h … Read more
A train travels 360 km at a uniform speed If the speed
Question 6:- A train travels 360 km at a uniform speed. If the speed had been 5 km/hr more, it would have taken 1 hours less for the same journey. Find the speed of the train. … Read more
A train covers a distance of 480 km at a uniform speed
Question 4:- A train covers a distance of 480 km at a uniform speed. If the speed had been 8 km/h less, it would have taken 3 hours more to cover the same distance. Find the original speed of the train. [CBSE 2020] Solution: Let the original … Read more