Adeuterium nucleus consists of one proton and
one neutron. the quark composition of a
deuterium nucleus is
(1) 2 up quarks and 2 down quarks
(2) 2 up quarks and 4 down quarks
(3) 3 up quarks and 3 down quarks
(4) 4 up quarks and 2 down quarks

A proton consists of 2 up quarks and 1 down quark.
A neutron consists of 1 up quark and 2 down quarks.

A deuterium nucleus consists of one proton and one neutron, so its quark composition is (3) 3 up quarks and 3 down quarks.

This did i unseated, sorry

Distance covered = speed x timethe distance traveled going against the stream = distance traveled with the stream.therefore it is the speed and the time that are the variables.as he travels the same distance both ways, speed x time is the same for each way.going upstream his speed is 4 kph; going downstream his speed is 6 kph.therefore we have two simultaneous equations: time upstream x 4 = time downstream x 6time upstream + time downstream = 60 minutestherefore we have the equation: time upstream = 6/10 hour, time downstream therefore = 4/10 hour.distance traveled at 4km/hr in 6/10 hour = 24/10 = 2.4km.check: distance traveled at 6km/hr in 4/10 hour = 24/10 = 2.4km.