25%×75%=18.75%;1-25%-18.75%=56.25%;40÷(56.25%-25%),=40÷31.25%,=128(张);128×25%=32(张);128×18.75%=24(张);128×56.25%=72(张);答:老大有32张,老二有72张,老三有24张.