problems with 'com.android.support:appcompat-v7.27.1.1' in the gradle file

when you hover over the red line it may show you the image like this which I have attached below.

What it tells you is there is a conflict of the version in some libraries so it suggests us to add those. For my case first, it showed for CardView and then for Design. So I added to it. Below is the code for it.

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.android.support.constraint:constraint-layout:1.1.0'
    implementation 'com.payumoney.sdkui:plug-n-play:1.2.0'
    implementation 'com.android.support:cardview-v7:27.1.1'
    implementation 'com.android.support:design:27.1.1'

    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

so kindly add those it may be 2 or more than that. Hope that helps.