Question

the average height of X number of girls and 15 boys is 123 cm. if the average height of boys is 125 cm and that if girls is 129 cm find the number of girls​

Answer 1

Answer:

FIRST OF ALL, CHECK THE QUESTION AGAIN...YOU HAVE REPLACED 126 CM BY 123 CM ( IN THE FIRST LINE ).

NUMBER OF GIRLS= 5

Step-by-step explanation:

AVERAGE HEIGHT OF 15 BOYS= 125CM

AVERAGE HEIGHT OF X GIRLS= 129CM

THEREFORE,

129X + (125*15) / (X+15) = 126

=> 129X + 1875 = 126X + 1890

=> 3X = 15

=> X = 5