The bongo family has three children, including a pair of twins. The third child is 3 years younger then the twins. The sum of the three ages is 42. How old is each child?

3 answers

a = age of the twins

b = age of the third child

b = a - 3

a + a + b = 42

2 a + b = 42

2 a + a - 3 = 42

3 a - 3 = 42

3 a = 42 + 3

3 a = 45 Divide both sides by 3

a = 45 / 3

a = 15

b = 15 - 3

b = 12
the first of two films lasted 9 minutes less than twice as long as the second. the combined length of the two films plus a 5-minute break between them was 260 minutes. how long was the first film?
x + 2x - 9 + 5 = 260

3x - 4 = 260

3x = 264

x = 88