(But 2 for 1)
1) If now Jenny is twice as old as Leo, and 5 years ago she was three times as old as he was, how old are they now?

2.) Liza comes to the swimming pool once every 6 days. Jenny comes once every 4 days and Olga comes once every 10 days. This Monday all of them were in the pool.
a.) How many days after this Monday will all of them meet at the swimming pool again?

1. Jenny is 20 and Leo is 10 years old now

2. They'll meet at the 60th day after their last meeting on Monday

Step-by-step explanation:

1.

Given

Let J represents Jenny and L represents Leo

From the question;

J = 2L Now

J - 5 = 3(L - 5) --- 5 years ago

Required

Find J and L

Substitute 2L for J in the second equation.

This gives

2L - 5 = 3(L - 5)

Open bracket

2L - 5 = 3L - 15

Add 15 - 2L to both sides

2L - 5 + 15 - 2L = 3L - 15 + 15 - 2L

Collect like terms

2L - 2L - 5 + 15 = 3L - 2L - 15 + 15

10 = L

L = 10

Substitute 10 for L in J = 2L

J = 2 * 10

J = 20

Hence, Leo is currently 10 years old and Jenny is currently 20 years old.

2. Give

Liza = once every 6 days.

Jenny = once every 4 days

Olga = once every 10 days.

Required

When next will they meet

This question implied that the we get the least common factor of the given data.

Liza = 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72

Jenny. = 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64

Olga = 10, 20, 30, 40, 50, 60, 70, 80

From the above, 60 is the least common factor.

Hence, we'll conclude that they'll meet after 60 days.