Practice focused topic-wise MCQs with answers and explanations for quick revision and exam preparation.
Difficulty select karke sirf is topic ke focused MCQs practice karein. Score, timer aur explanations student-friendly flow me milenge.
Showing 391-400 of 600 questions.
If \(S_n-S_{n-1}=84\) and \(S_m=990\), what is (n-m)?
C. (40)
पहले (n=84) और \(S_m=990\) से (m=44), इसलिए (n-m=40)। लगातार योगों का अंतर सूचकांक देता है। / First (n=84), and \(S_m=990\) gives (m=44), so (n-m=40). The difference of consecutive sums gives the index.
Login to save your score, XP, coins and progress.
Which sum is obtained by adding (76+77+78+79+80) to \(S_{75}\)?
C. \(S_{80}\)
\(S_{75}+76+77+78+79+80=S_{80}\) है। लगातार नए पद जुड़ने पर अंतिम पद नया सूचकांक बनता है। / \(S_{75}+76+77+78+79+80=S_{80}\). When consecutive new terms are added, the last term becomes the new index.
Login to save your score, XP, coins and progress.
If \(S_n=2926\), what is the value of (n)?
C. (76)
\(S_{76}=\frac{76\times77}{2}=2926\) इसलिए (n=76) है। बड़े मानों में \(2S_n\) से पहचान आसान होती है। / \(S_{76}=\frac{76\times77}{2}=2926\), so (n=76). For large values, using \(2S_n\) makes identification easier.
Login to save your score, XP, coins and progress.
Find the value of \(S_{19}+S_{39}+S_{59}\).
A. (2740)
\(S_{19}=190\), \(S_{39}=780\) और \(S_{59}=1770\), इसलिए कुल (2740) है। तीन अलग सूचकांकों को ध्यान से जोड़ें। / \(S_{19}=190\), \(S_{39}=780\), and \(S_{59}=1770\), so the total is (2740). Add the three different indices carefully.
Login to save your score, XP, coins and progress.
The sum of the first (n) natural numbers is (4656). What is the value of (n-10)?
B. (86)
\(S_{96}=4656\) इसलिए (n=96) और (n-10=86)। पहले (n) निकालें फिर पूछा गया मान दें। / \(S_{96}=4656\), so (n=96) and (n-10=86). Find (n) first and then answer what is asked.
Login to save your score, XP, coins and progress.
If \(S_{n+1}-S_{n-1}=151\), what will be the value of (n)?
B. (75)
अंतर (n+(n+1)=2n+1) है, इसलिए (2n+1=151) से (n=75)। दो पदों के अंतर को सीधे लिखें। / The difference is (n+(n+1)=2n+1), so (2n+1=151) gives (n=75). Write the two-term difference directly.
Login to save your score, XP, coins and progress.
What is the value of \(S_{200}-S_{190}\)?
A. (1955)
अंतर \(191+192+\cdots+200=1955\) है। बड़े सूचकांक में भी केवल बीच के पद जोड़ने होते हैं। / The difference is \(191+192+\cdots+200=1955\). Even with large indices, only the terms in between need to be added.
Login to save your score, XP, coins and progress.
If \(S_n=6216\), what is the value of (n)?
B. (111)
\(S_{111}=\frac{111\times112}{2}=6216\) इसलिए (n=111) है। \(2S_n\) से क्रमागत संख्याओं की पहचान करें। / \(S_{111}=\frac{111\times112}{2}=6216\), so (n=111). Use \(2S_n\) to identify consecutive numbers.
Login to save your score, XP, coins and progress.
What is (3) times the difference between \(S_{48}\) and \(S_{24}\)?
B. (2628)
\(S_{48}-S_{24}=1176-300=876\) और \(3\times876=2628\) है। पहले अंतर निकालें फिर गुणा करें। / \(S_{48}-S_{24}=1176-300=876\), and \(3\times876=2628\). First find the difference and then multiply.
Login to save your score, XP, coins and progress.
If \(S_y=4950\), what will be the value of \(S_{y+1}\)?
C. (5050)
\(S_{99}=4950\) है इसलिए \(S_{100}=4950+100=5050\)। अगले योग के लिए अगला पद जोड़ें। / \(S_{99}=4950\), so \(S_{100}=4950+100=5050\). For the next sum, add the next term.
Login to save your score, XP, coins and progress.
Use Google login or mobile OTP. Admin can block users and control login providers.