Step-by-step explanation:
in a geometric sequence there is a constant factor x that is multiplied with every previous term to create the next one.
a2 = 20
a5 = 1280 = a2×x×x×x = a2×x³ = 20x³
64 = x³
x = 4
=> a1 = 5
therefore
an = an-1×4 =
n > 1
What is the value for y? Enter your answer in the box.
2 answers:
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Answer:
9 labours
Step-by-step explanation:
In order to solve this, we must know which kind of proportionality is this. There are two types of proportions, direct and indirect/inverse proportions. In direct proportion, if one quantity increases, the other quantity also increases.
In indirect proportion, if one quantity increases, the other decreases and vice versa.
As per this question, we know if the number of labour increases, the number of days to complete a work decreases, thus proving that this is an indirect/inverse proportion.
6 labours => 12 days
x labours => 8 days
Since its an inverse proprotion, multiply 6 with 12, and x with 8.
8x = 6 × 12
x =
∴ x = <u>9 labours</u>