Pls answer quick 45 points :))

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?

Calculate the effective quarterly compound interest rate equivalent to a 1% of monthly compound interest rate.

Martha is training for a duathlon, which includes biking and running. she knows that yesterday she covered a total distance of over 55.5 miles in more than than 4.5 hours of training. martha runs at a speed of 6 mph and bikes at a rate of 15.5 mph.