Q: It took a patrol boat 5 hours to travel 60 km up a river against the current, and 3 hours for the return trip with the current. Determine the speed of the boat in still water and the speed of the current. Let x be the speed of the boat in still water in km/hr
Let y be the speed of the current in km/hr.

*the 2 equations are x+y=20 and x-y=12 however I don’t understand why. Can someone explain?

Sunday: 1 1 2 monday: 1 tuesday: 2 1 2 wednesday: 1 3 4 thursday: 2 friday: 1 1 2 saturday: 2 jenna is a swimmer and trains every day. the schedule shown outlines the number of hours she trains each day. what is the total number of hours that jenna trains during the week?

Last week jason walked 3 1/4 miles each day for 3 days and 4 5/8 miles each day for 4 days. about how many miles did jason walk last week?

According to a research study, parents with young children slept 6.4 hours each night last year, on average. a random sample of 18 parents with young children was surveyed and the mean amount of time per night each parent slept was 6.8. this data has a sample standard deviation of 0.9. (assume that the scores are normally distributed.) researchers conduct a one-mean hypothesis at the 5% significance level, to test if the mean amount of time parents with young children sleep per night is greater than the mean amount of time last year. the null and alternative hypotheses are h0: μ=6.4 and ha: μ> 6.4, which is a right-tailed test. the test statistic is determined to be t0=1.89 using the partial t-table below, determine the critical value(s). if there is only one critical value, leave the second answer box blank.