there is enough provisions for 1200 girls in a hostel for 50 days . if there were 600 girls less , how long will the provision last ?
"we have , m 1 d 1 = m 2 d 2 1200 * 50 = 600 * d 2 d 2 = 1200 * 50 / 600 = 100 days . answer : e"
add(divide(multiply(1200, 600), const_10), 50)