red=x, 3x=60,x=20. eq...(1).
blue=y, x+2y=30, but x=20 then 20+2y=30, 2y=30-20, 2y=10, y=5. eq..(2).
yelow=z, then y-z=5-3=2
finalize yelow+red*blue= 2+20*5=102.
finaly red=20, blue=5 and yellow=2 which gives you 102 kasimu kangu kamchine kwa hyo ukichukua 102-1 =101 ndio jibu