Afamily pays $45 each month for cable television. the cost increases 7% . what is the new monthly cost?

Pls! does anybody know a shortcut for answering these types of questions in the future?

During a bike challenge riders have to collect various colored ribbons each 1/2 mile they collect a red ribbon each eighth mile they collect a green ribbon and each quarter mile they collect a blue ribbion wich colors of ribion will be collected at the 3/4 markrer

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?