Home›UPSC Prelims›Paper 2: General Studies II (CSAT)›Civil Services Aptitude Test (CSAT)›Basic Numeracy & Data Interpretation›What is the smallest number greater than 1000 that when divided by

What is the smallest number greater than 1000 that when divided by any one of the numbers 6, 9, 12, 15, 18 leaves a remainder of 3?

20223Mprelimsupscyear-2022p2quantitative-aptitudequantitative-abilitynumbers
A.1063
B.1073
C.1083Correct
D.1183
Explanation & Solution

The correct answer is (C) 1083.

Explanation:

First, we find the LCM of 6, 9, 12, 15, and 18. Prime factorizations: 6 = 2×3, 9 = 3^2, 12 = 2^2×3, 15 = 3×5, 18 = 2×3^2. LCM = 2^2 × 3^2 × 5 = 4 × 9 × 5 = 180. We need the smallest number greater than 1000 that leaves a remainder of 3 when divided by 180. Let k be an integer such that 180k + 3 > 1000. For k = 5, 180 × 5 + 3 = 903 (not greater than 1000). For k = 6, 180 × 6 + 3 = 1080 + 3 = 1083. Wait, let us check k=5: 903. For k=6: 1083. Is there a smaller multiple? Let's check 180×5 = 900, 180×6 = 1080. 1080 + 3 = 1083. Let us check option 1073: 1073 - 3 = 1070, is 1070 divisible by 180? No. Let's check 1083 - 3 = 1080, which is divisible by 180 (180 × 6 = 1080). Thus 1083 leaves remainder 3 and is greater than 1000.

हिंदी में प्रश्न एवं आदर्श उत्तर

1000 से बड़ी वह लघुतम संख्या कौन-सी है जिसे 6, 9, 12, 15, 18 में से किसी एक से भी विभाजित करें, तो शेषफल 3 बचे?

A.1063
B.1073
C.1083सही
D.1183

सही उत्तर (C) 1083 है।

व्याख्या:

First, we find the LCM of 6, 9, 12, 15, and 18. Prime factorizations: 6 = 2×3, 9 = 3^2, 12 = 2^2×3, 15 = 3×5, 18 = 2×3^2. LCM = 2^2 × 3^2 × 5 = 4 × 9 × 5 = 180. We need the smallest number greater than 1000 that leaves a remainder of 3 when divided by 180. Let k be an integer such that 180k + 3 > 1000. For k = 5, 180 × 5 + 3 = 903 (not greater than 1000). For k = 6, 180 × 6 + 3 = 1080 + 3 = 1083. Wait, let us check k=5: 903. For k=6: 1083. Is there a smaller multiple? Let's check 180×5 = 900, 180×6 = 1080. 1080 + 3 = 1083. Let us check option 1073: 1073 - 3 = 1070, is 1070 divisible by 180? No. Let's check 1083 - 3 = 1080, which is divisible by 180 (180 × 6 = 1080). Thus 1083 leaves remainder 3 and is greater than 1000.

See this question in context →
Free Android App

Practice Better on the StatePYQ Mobile App

⚡ Error Diary · ⏱ Timed Mains Answer Pacer · 📴 Offline Revision Vault

Get it onGoogle Play