Subtract four from both sides. That'll put both numbers without a variable on one side, and the number with the variable is by itself.
Let the number of thirds be x.
(2/5) = x(1/3)
2/5 = x/3
x/3 = 2/5
x = 2/5 * 3
x = 6/5
x = 1.2
Two-fifths equals 1.2 thirds
Answer: b) 160 c) 1500
Step-by-step explanation: b) 50 + 50 + 30 + 30 = 160 c) 50 x 30 = 1500