Answer:
105
Explanation:
Let x, y and z be the 3 numbers in the order first, second and third
x + y + z = 180
Second number y is 3 times the smallest number and third number z is 7 times the smallest number. So smallest number has to be x
so y = 4x
z = 7x
x + y + z = x + 4x + 7x = 180
12x = 180
x = 15
Largest number = 7 x 15 = 105