First thing to note is to understand the formula we can use for percentage increase. The final is May, and initial is April. So we can put in the numbers now. Then, remember how to bring numbers over. We start by dividing 40 percent by 100. Then we bring 50 over from the denominator, so 0.4 times 50. Then we bring 50 over and add it to 20. So you have 70. Hope it helps!