Final answer:
Lawal earns 1200 naira monthly.
Step-by-step explanation:
To solve this problem, we can work backwards from the final amount in Lawal's pocket. Let's denote Lawal's monthly salary as 'x'. He spends 3/4 of x on food, so he has x - (3/4)x = (1/4)x remaining. He then spends 1/2 of the remainder on rent, so he has (1/4)x - (1/2)((1/4)x) = (1/4)x - (1/8)x = (1/8)x remaining. Since he has 150 naira left, we can set up the equation:
(1/8)x = 150
To solve for x, we can multiply both sides of the equation by 8:
x = 150 * 8 = 1200
Therefore, Lawal earns 1200 naira monthly.
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