Math Riddles

Question: if Donald trump has 57 dollars and he spends 26 dollars and the cashier guy gives him 36 cents back, how much money does he have?

Question: A pond with dimension of 6m by 3m wil be filled of water lilies at exactly 30 days. Each day the number of water lilies will be doubled. First day 1, second day 2 etc... On what day it will fill half of the pond?

Question: At low tide 14 rungs of a ship are above the water, the rungs are 15 centimeters apart. each 15 mins the water rises 15 centimeters. after 2 hours and 30 mins how many rungs are above the water?

Question: this is a 6 digit number. this number has two decimal places. there are no tenths or tens in this number. the tenths digit plus the hundredth digit equals 6. if you divide the thousands digit by 2 the answer is 2. the hundreds digit is the same as today's date. the units digit is half the hundredths unit.

Question: When i was 4 my sister was half my age. Now I am 100. How old is my sister now?