Question

There are 100 coins in a jar and 10 are dimes. The rest are pennies and nickles. There are twice as many pennies as nickels. How many pennies and nickles are in the jar?

Answer 1

p + n = 90
p = 2 n

3 n = 90
n = 30

p = 60

Answer 2

Thank you, can you please explain where the number 3 came from? Thank you so much!

Answer 3

p + n = 90
but we know that p is 2 n
so
2n + n = 90
or
3 n = 90

Answer 4

Thank you very much!