Answer:
Step-by-step explanation:
What we have is a general equation that says this in words:
Laura's hours + Doug's hours = 250 total hours
Since we don't know either person's number of hours, AND since we can only have 1 unknown in a single equation, we need to write Laura's hours in terms of Doug's, or Doug's hours in terms of Laura's. We are told that Doug spent Laura's hours plus another 40 in the lab, so let's call Laura's hours "x". That makes Doug's hours "x + 40". Now we can write our general equation in terms of x:
x + x + 40 = 250 and
2x = 210 so
x = 105
Since Laura is x, she worked 105 hours in the lab and Doug worked 40 hours beyond what Laura worked. Doug worked 145. As long as those 2 numbers add up to 250, we did the job correctly. 105 + 145 = 250? I believe it does!!
4) Answer is D.
Irrational numbers cannot be classified as rational numbers
5) Answer is B.
Every irrational number is a real number
Answer:
The answer is below
Step-by-step explanation:
a) Cost of hiring the bicycle for 14 days is:
Cost = 65 * 14 days + 44 = 954 riyals
b) The number of days the bicycle is hired is to be the same as the number of days the bicycle is to be hired. Let us assume that the bicycle and helmet is to be hired for x days, hence:
Cost of bicycle = 65 * x + 14 = 65x + 44
Cost of helmet = 12.5 * x = 12.5x
Total cost = 65x + 44 + 12.5x = 77.5x + 44
Since 750 riyals is available, hence:
750 = 77.5x + 44
77.5x = 706
x = 9.11
Therefore the maximum number of days is 11. The total cost for 11 days is:
Total cost = 77.5(9) + 44 = 741.5 riyals
Money not spent = 750 riyals - 741.5 riyals = 8.5 riyals