Do you think the answer is C.147?
Answer:
He will finish the rest of the problems in 32.4 minutes.
Step-by-step explanation:
Since we are given that Yan has completed 3/5 of 45 problems i.e.
Thus he has completed 27 problems
Remaining no. of problems are 45-27 = 18
Since he complete each problem in minutes = 
So, he completes 18 problems in minutes = 18 *1.8 = 32.4 minutes
Hence , He will finish the rest of the problems in 32.4 minutes.
Answer:
The provided study is an experiment.
Step-by-step explanation:
Consider the provided information.
Observational study: In this study observer only observe the subjects, and measure variables of interest without allocating treatments to subjects.
For example: you want to examine the side effect of smoke on lung.
Experiment study:The researchers are applying treatments to experimental units in the research, then the effect of the treatments on the experimental units is observed.
For example: Flipping a coin
Now consider the provided information:
Thirty university students are divided into two groups. One group receives free tutoring in mathematics comma the other doesn't. After one semester comma scores on final mathematical examinations are compared.
Here, the researcher applying treatment to experimental units.
Thus, the provided study is an experiment.
Cosα=x/L
L=x/cosα, we are told that the ladder base is 48 ft from the base of the wall and α=39° so:
L=48/cos39 ft
L≈61.76 ft (to nearest hundredth of a foot)
