有a,b,c三个数,a:b=4:3,b:c=2:5,a+b+c=29/15,b=( )

有a,b,c三个数,a:b=4:3,b:c=2:5,a+b+c=29/15,b=( )
有a,b,c三个数,a:b=4:3,b:c=2:5,a+b+c=29/15,b=( )

有a,b,c三个数,a:b=4:3,b:c=2:5,a+b+c=29/15,b=( )
∵a:b=4:3
∴a=4/3b
∵b:c=2:5
∴c=2/5b
∴a+b+c
=4/3b+b+2/5b
=(4/3+1+2/5)b
=(20/15+15/15+6/15)b
=41/15b
=29/15
∴b=29/15x15/41=29/41