Answer:
sister = 6 years
John=18 years
Step-by-step explanation:
A(S) + 12 = 3 * A(S), subtracting A(S) from both sides one gets 12 = 2 * A(S). Now dividing both sides by 2 we get A(S) = 12/2 = 6 . Therefore, the age of the sister is 6 years when her brother John is three times as old, that is 18 years.
Answer:
Step-by-step explanation:
42:7=ED:24
cross multiply 42 into 24.
Then divide by 7
you will get ED
Then use pythageorous theorem.
Ed square + 42 square=Ef square
Then do square root of Ef square
You have 11 items and you need to choose 5 of the 11.
There are 462 ways to choose them.
The formula is :
11! / (5!6!)
n!/(r!(n-r)!)
