280 mangoes are divided among some boys and girls whose total number is 50 so that each boy gets 5 mangoes and each girl get 7 mangoes. The number of girls is
Answer & explanation
Correct answer: option 1
According to the question:
B + G = 50 ----(i)
5B + 7G = 280 ----(ii)
Multiplying 1 equation by 5 so we get:
5B + 5G = 250 -----(iii)
5B + 7G = 280 ------(iv)
Subtracting (iii) from (iv)
5B + 7G - 5B - 5G = 280 - 250
2G = 30
G = 15