Exponential growth or decay?

Y=3^t

Three coins are flipped. what is the probability that there will be at least two tails?

Arley is building a model of a city map. in one part of the city, three roads form a right triangle, which harley draws as triangle abc, with the following measures: m∠b=90° and m∠a=30°. in his scale model, the hypotenuse of triangle abc, ac¯¯¯¯¯¯¯¯, has a length of 817−−√ cm. what is the value of a (the length of bc¯¯¯¯¯¯¯¯)?

The sides of a parallelogram are 24cm and 16cm. the distance between the 24cm sides is 8 cm. find the distance between the 16cm sides