Answer:
6 weeks
Step-by-step explanation:
Set up a proportion where x is the amount of time with 12 pupils:
= 
Cross multiply and solve for x:
4x = 24
x = 6
So, it will take 12 pupils 6 weeks to complete the job.
Answer:
805.2
Step-by-step explanation:
7 added to a number, 7 plus a number, 7 and a number, etc. It's written in many ways.
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sorry if this doesn't help
Answer:
The 50th term is 288.
Step-by-step explanation:
A sequence that each term is related with the prior by a sum of a constant ratio is called a arithmetic progression, the sequence in this problem is one of those. In order to calculate the nth term of a setence like that we need to use the following formula:
an = a1 + (n-1)*r
Where an is the nth term, a1 is the first term, n is the position of the term in the sequence and r is the ratio between the numbers. In this case:
a50 = -6 + (50 - 1)*6
a50 = -6 + 49*6
a50 = -6 + 294
a50 = 288
The 50th term is 288.
7 + 28n + 4
28n + (7 + 4)
28n + 11