N+3=28 what does n equal

Asix-sided die of unknown bias is rolled 20 times, and the number 3 comes up 6 times. in the next three rounds (the die is rolled 20 times in each round), the number 3 comes up 6 times, 5 times, and 7 times. the experimental probability of rolling a 3 is 10 %, which is approximately % more than its theoretical probability. (round off your answers to the nearest integer.)

Jackson earns $25 per hour as a tutor at the college library. he set a weekly spending budget of $130 each week and puts the remaining money in his savings account. how many hours must he work this week to have at least an extra $50 to put in his savings account

Acollection of nickels and quarters is worth $2.85. there are 3 more nickels than quarters.how many nickels and quarters are there?