We require #250*mL# of a #6.0*mol*L^-1# solution (with respect to #H_2SO_4)#.

With respect to #H_2SO_4#, this represents a molar quantity of #0.250*Lxx6.0*mol*L^-1=1.50*mol#.

If the mother solution has a #18*mol*L^-1# concentration, then we solve the quotient, #(1.50*cancel(mol))/(18*cancel(mol)*cancel(L^-1))xx1000*mL*cancel(L^-1)=??*mL#.

Alternatively we could use the following formula for the molar equivalence:

#C_1V_1=C_2V_2#.............

#"Important, so get it right................."#

#"WHEN YOU DO THESE DILUTIONS YOU ALWAYS ADD"#

#"ACID TO WATER!!!!"#

#"Why?"# BECAUSE IF YOU SPIT IN ACID IT SPITS BACK AT YOU. I am not joking.