janet sends parcels by parcel express.
the table shows information about the cost of sending a parcel by parcel express.

parcel express
weight range cost
less than 2 kg £3.80
2 kg to less than 5 kg £5.99
5 kg to 10 kg £7.14

the table below gives information about the numbers and weights of the parcels janet sent in april and in may.

number of parcels
weight range april may
less than 2 kg 23 21
2 kg to less than 5 kg 28 27
5 kg to 10 kg 19 32

janet could have sent her parcels by parcels r go.
the table below shows information about the cost of sending a parcel by parcels r go.

parcels r go
weight range cost
0–15 kg £5.99

janet thinks that it would have been cheaper to send all her parcels by parcels r go.

is janet right?
you must show your working.