In the left hand side, you're multiplying 7.8 by 
In the right hand side, you're multiplying again 7.8 by a mysterious number.
So, the unknown number must be 
Every number remains unchanged when multiplied by 1, so the answer is 3.6
The question asks for the rate of toys per hour.
So we shall divide the total toys assembled by the total hours.
Its a five day week.
The number of hours allotted per day are 8.
So total allotted during the week are 8 × 5 = 40 hours.
Number of toys made during the week are 400.
Hence the number of toys assembled per hour per person
= number of toys / number of hours
= 400 / 40
= 10 toys per hour per person.
The average number of toys assembled per hour per person is 10.
Answer:
She spent 2 and a half hours doing extra work.
8 is 6.2
9 is 7
The pattern here is +0.8.
4.6 - 3.8=0.8
5.4-4.6=0.8, and so on