Review: divisibility and fractions with different denominators
Answers are for parents and teachers.
1
Is 5,940 divisible by 9? By 6?
By 9 yes (digit sum 18); by 6 yes too (it is even and its digit sum is divisible by 3, so it is divisible by both 2 and 3).
2
Find GCD(48, 72) and LCM(48, 72).
GCD = 24 and LCM = 144.
3
Compute 5/8 + 7/12.
1 5/24
4
Compute 5 1/3 − 2 5/6.
2 1/2
5
Two buses leave every 12 and 18 minutes. They left together at 8:00. When do they next leave together?
At 8:36 (LCM = 36 minutes).