How many multiples of $4$ lie between $10$ and $250$?
Step-by-Step Solution
Key Concept: Multiples: $12, 16, \dots, 248$. $a = 12, d = 4, l = 248$. $248 = 12 + (n - 1)4 \Rightarrow (n - 1)4 = 236 \Rightarrow n - 1 = 59 \Rightarrow n = 60$.
$12 + (n - 1)4 = 248 \Rightarrow (n - 1)4 = 236 \Rightarrow n - 1 = 59$. [1.0 Mark]
$n = 60$. There are $60$ multiples of 4. [1.0 Mark]
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🎯 Official CBSE Marking Scheme:
Setting equation $12 + 4(n-1) = 248$: 1.0 Mark
Solving $n = 60$: 1.0 Mark
Correct Answer: