Three rivers R1,R2 and R3 merge together to form a river, R4. The cross sectional areas of the three rivers R1,R2 and R3 are in the ratio 1:2:3 and speed of water flowing in these are in the ratio 1:12:13. Assuming streamline flow, if R4 has cross sectional area equal to that of R1, the ratio of speed of water in R4 to that in R1 is