Final answer:
To find out how many students rode a bus to school when 45% of 640 students walked, calculate 45% of 640, which is 288 students walking, and subtract from the total to get 352 students riding the bus.
Step-by-step explanation:
The student has asked how many students rode in a bus to school if 45% of the total number of students walked to school on a certain Friday, given that there were 640 students in total.
To find the number of students who rode the bus, we have to first calculate the number of students who walked to school by taking 45% of the total number of students, which is 45/100 times 640.
After finding this number, we then subtract it from the total number of students to find out how many took the bus.
Step 1: Calculate the number of students who walked:
45% of 640 = 0.45 × 640 = 288
Step 2: Calculate the number of students who took the bus:
640 - 288 = 352
Therefore, the number of students who rode in a bus to school is 352.