Muft Shiksha
Update

Muft Shiksha™ एक 100% Free Education Portal है 🇮🇳, जिसका उद्देश्य Class 9–12 के हर विद्यार्थी तक High-Quality Education को पूरी तरह मुफ्त पहुँचाना है। 🇮🇳 हम मानते हैं कि अच्छी शिक्षा किसी student की आर्थिक स्थिति पर निर्भर नहीं होनी चाहिए। 🇮🇳 हर विद्यार्थी को वही Quality Study Material, MCQs, Quizzes, Exam Preparation, Concept-Based Learning और Bilingual Support मिलना चाहिए, जो आमतौर पर महंगी Coaching या Premium Platforms में मिलता है। Muft Shiksha™ 🇮🇳 इसी सोच के साथ बनाया गया है

Subjects
Class 10MathematicsArithmetic Progressions (AP)Word problems based on APsExpert
0 reads0 ratings0 helpful

A stepped wall has (210) stones in the bottom row and (10) fewer stones in each upper row. Which row will have (70) stones?

Answer and explanation

Correct answer: 15

The numbers of stones form a decreasing AP from the bottom, with \(a=210\) and \(d=-10\). For the \(n\)th row, \(a_n=210+(n-1)(-10)\). Using \(210-10(n-1)=70\) gives \(n-1=14\), so \(n=15\). Hence, the 15th row has 70 stones. The 14th row would have 80 stones, so it is not correct. Exam tip: use a negative common difference for an AP that decreases upward.

Related tags

Arithmetic ProgressionAp Word ProblemsDecreasing ApNth TermStepped WallWord Problems Based On ApsArithmetic Progressions (Ap)Arithmetic Progressions Ap
सुधार सुझाएँ / Earn

Was this question useful?

No ratings yetWrite a review / Rate this question

Student Reviews

No published reviews yet.

KEEP PRACTISING

10 more MCQs
  1. 1A farmer plants (4) more plants each day. If he plants (6) plants on the first day, what will the sequence be?
  2. 2In an elevator test, the first cycle has 240 kg load and 15 kg is reduced in each next cycle. In which cycle will the load be 75 kg?
  3. 3In an experiment, the temperature is 760 units at the first stage and decreases by 32 units at each next stage. At which stage will it be 280 units?
  4. 4A student solves 42 questions on the first day and 9 more questions each day. On which day will he solve 276 questions?
  5. 5In a machine, the load is 980 units at the first stage and decreases by 45 units at each next stage. At which stage will the load be 305 units?
  6. 6In a test, the value is 1250 units at the first stage and decreases by 55 units at each next stage. At which stage will the value be 260 units?
  7. 7A student solves 64 questions on the first day and 15 more questions each day. On which day will he solve 514 questions?
  8. 8The first row of an auditorium has (10) seats and each next row has (2) more seats. How many seats are there in (15) rows?
  9. 9Ravi saves 20 rupees on the first day and 5 rupees more each next day. What will be his total saving in 10 days?
  10. 10A gardener plants (6) plants in the first row and (3) more plants in each next row. How many plants are planted in (8) rows?
Found an issue? Help improve this questionMy reports and replies

Add Muft Shiksha to your Home Screen

In Safari, tap Share, then Add to Home Screen.