the average height of 15 girls out of a class of 30 is 152 cm . and that of the remaining girls is 156 cm . the average height of the whole class is :
"explanation : average height of the whole class = ( 15 × 152 + 15 × 156 / 30 ) = 154 cms answer d"
divide(add(multiply(152, 15), multiply(156, const_10)), 30)