CHAPTER-5 ARITHMETIC PROGESSIONS QUESTION -16 Determine the A.P. whose third term is 16 and the 7th term exceeds the 5th term by 12. ANSWER: =a3 = 16a + (3 − 1) d = 16a + 2d = 16 (1)a7 − a5 = 12[a+ (7 − 1) d] − [a + […]
CLASS-10 MATH’S EXERCISE 5.2 Q-14
CHAPTER-5 ARITHMETIC PROGESSIONS QUESTION -14 How many multiples of 4 lie between 10 and 250? ANSWER: First multiple of 4 that is greater than 10 is 12. Next will be 16.Therefore, 12, 16, 20, 24, …All these are divisible by 4 and thus, all these are terms of an A.P. […]
CLASS-10 MATH’S EXERCISE 5.2 Q-13
CHAPTER-5 ARITHMETIC PROGESSIONS QUESTION -13 How many three digit numbers are divisible by 7 ANSWER: First three-digit number that is divisible by 7 = 105Next number = 105 + 7 = 112Therefore, 105, 112, 119, …All are three digit numbers which are divisible by 7 and thus, all these are […]
CLASS-10 MATH’S EXERCISE 5.2 Q-10
CHAPTER-5 ARITHMETIC PROGESSIONS QUESTION -10 If 17th term of an A.P. exceeds its 10th term by 7. Find the common difference ANSWER: We know that,For an A.P., an = a + (n − 1) da17 = a + (17 − 1) da17 = a + 16dSimilarly, a10 = a + […]
CLASS-10 MATH’S EXERCISE 5.2 Q-9
CHAPTER-5 ARITHMETIC PROGESSIONS QUESTION -9 If the 3rd and the 9th terms of an A.P. are 4 and − 8 respectively. Which term of this A.P. is zero. ANSWER: Given that,a3 = 4a9 = −8We know that,an = a + (n − 1) da3 = a + (3 − 1) […]
CLASS-10 MATH’S EXERCISE 5.2 Q-8
CHAPTER-5 ARITHMETIC PROGESSIONS QUESTION -8 An A.P. consists of 50 terms of which 3rd term is 12 and the last term is 106. Find the 29th term ANSWER: Given that,a3 = 12a50 = 106We know that,an = a + (n − 1) da3 = a + (3 − 1) d12 […]
CLASS-10 MATH’S EXERCISE 5.2 Q-7
CHAPTER-5 ARITHMETIC PROGESSIONS QUESTION -7 Find the 31st term of an A.P. whose 11th term is 38 and the 16th term is 73 ANSWER: Given that,a11 = 38a16 = 73 We know that,an = a + (n − 1) da11 = a + (11 − 1) d38 = a + […]
CLASS-10 MATH’S EXERCISE 5.2 Q-6
CHAPTER-5 ARITHMETIC PROGESSIONS QUESTION -6 Check whether − 150 is a term of the A.P. 11, 8, 5, 2, … ANSWER: For this A.P.,a = 11d = a2 − a1 = 8 − 11 = −3Let −150 be the nth term of this A.P. We know that, Clearly, n is […]
CLASS-10 MATH’S EXERCISE 5.2 Q-5
CHAPTER-5 ARITHMETIC PROGESSIONS QUESTION -5 Find the number of terms in each of the following A.P. ANSWER: I. 7, 13, 19, …, 205For this A.P.,a = 7d = a2 − a1 = 13 − 7 = 6 Let there are n terms in this A.P. an = 205We know thatan […]
CLASS-10 MATH’S EXERCISE 5.2 Q-4
CHAPTER-5 ARITHMETIC PROGESSIONS QUESTION -4 Which term of the A.P. 3, 8, 13, 18, … is 78? ANSWER: 3, 8, 13, 18, …For this A.P.,a = 3d = a2 − a1 = 8 − 3 = 5 Let nth term of this A.P. be 78. Hence, 16th term of this […]