the combined mean and variance of salary of 250 workers of city A and B are 560 and 5497 respectively. The mean and variance of the salary of 1850 workers of city B are 581 respectively. Find the variance of salary in city a.​

Afew buddies come over to your house to hang out. they notice you're struggling in school, perhaps you have to rely on to pass your class, but you can't absorb the knowledge. they could positively reinforce getting a tutor and working with you, dedicating more time to the areas of struggle and less on hanging out to better yourself.secondly, say you're the victim of bullying. you're afraid to tell an adult because of possible repercussions from the bully himself. your friends encouraging you and pushing you towards telling an adult for your safety is another example. 

So that you don't get baby's but also prevents stis such as hiv

Is there anything else you can add to ?