Wang Lei and Amira were asked to find an explicit formula for the sequence 30,150,750,3750,…, where the first term should be g(1).Wang Lei said the formula is g(n)=30⋅5(n−1), andAmira said the formula is g(n)=6⋅5n.Which one of them is right?Choose 1 answer:(A) Only Wang Lei(B) Only Amira(C) Both Wang Lei and Amira(D) Neither Wang Lei nor Amira
Q. Wang Lei and Amira were asked to find an explicit formula for the sequence 30,150,750,3750,…, where the first term should be g(1).Wang Lei said the formula is g(n)=30⋅5(n−1), andAmira said the formula is g(n)=6⋅5n.Which one of them is right?Choose 1 answer:(A) Only Wang Lei(B) Only Amira(C) Both Wang Lei and Amira(D) Neither Wang Lei nor Amira
Analyze sequence type: Analyze the sequence to determine if it is arithmetic or geometric.The sequence is 30,150,750,3750,…To determine if the sequence is arithmetic or geometric, we look at the ratio of consecutive terms.30150=5150750=57503750=5Since each term is multiplied by 5 to get the next term, the sequence is geometric.
Determine first term and common ratio: Determine the first term and the common ratio of the sequence.The first term g(1) is 30.The common ratio r is the factor we multiply by to get from one term to the next, which we have determined to be 5.
Evaluate Wang Lei's formula: Evaluate Wang Lei's formula.Wang Lei's formula is g(n)=30⋅5(n−1).Let's check if this formula works for the first few terms:For n=1: g(1)=30⋅5(1−1)=30⋅50=30⋅1=30For n=2: g(2)=30⋅5(2−1)=30⋅51=30⋅5=150For n=3: g(3)=30⋅5(3−1)=30⋅52=30⋅25=750Wang Lei's formula correctly generates the sequence.
Evaluate Amira's formula: Evaluate Amira's formula.Amira's formula is g(n)=6⋅5n.Let's check if this formula works for the first few terms:For n=1: g(1)=6⋅51=6⋅5=30For n=2: g(2)=6⋅52=6⋅25=150For n=3: g(3)=6⋅53=6⋅125=750Amira's formula also correctly generates the sequence.
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