Question-Answer

Question 1: Evaluate: Solution: Let I = .   .   . (i) Using property I = ⇒  I = ⇒ I = ⇒  Dividing by in numerator and denominator ⇒ ……..(ii) Let The limits are, when

Question 10: A sum of ₹ 4,250 is to be used to give 10 cash prizes to students of a school for their overall academic performance. If each prize is ₹ 50 less than its preceding prize, find the value of each of the prizes.                [CBSE     2017] … Read more

Question 9: A child puts one five-rupees coin of her savings in the piggy bank on the first day. She increases her saving by one five-rupee coin daily. If the piggy bank can hold 190 coins of five rupees in all, find the number of days she can continue to put the five -rupee coins … Read more

Question 8: Yasmeen saves ₹ 32 during the first month ₹ 36 in the second month and ₹ 40 in the third month. If she continues to save in this manner, in how many months will she save ₹ 2000? Answer : Since, Hence, A.P.  32, 36, 40 .   .  . a = 32, d … Read more

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

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

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

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

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